1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
4 *
5 * Test code for seccomp bpf.
6 */
7
8 #define _GNU_SOURCE
9 #include <sys/types.h>
10
11 /*
12 * glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
13 * we need to use the kernel's siginfo.h file and trick glibc
14 * into accepting it.
15 */
16 #if !__GLIBC_PREREQ(2, 26)
17 # include <asm/siginfo.h>
18 # define __have_siginfo_t 1
19 # define __have_sigval_t 1
20 # define __have_sigevent_t 1
21 #endif
22
23 #include <errno.h>
24 #include <linux/filter.h>
25 #include <sys/prctl.h>
26 #include <sys/ptrace.h>
27 #include <sys/time.h>
28 #include <sys/user.h>
29 #include <linux/prctl.h>
30 #include <linux/ptrace.h>
31 #include <linux/seccomp.h>
32 #include <pthread.h>
33 #include <semaphore.h>
34 #include <signal.h>
35 #include <stddef.h>
36 #include <stdbool.h>
37 #include <string.h>
38 #include <time.h>
39 #include <limits.h>
40 #include <linux/elf.h>
41 #include <sys/uio.h>
42 #include <sys/utsname.h>
43 #include <sys/fcntl.h>
44 #include <sys/mman.h>
45 #include <sys/times.h>
46 #include <sys/socket.h>
47 #include <sys/ioctl.h>
48 #include <linux/kcmp.h>
49 #include <sys/resource.h>
50 #include <sys/capability.h>
51 #include <linux/perf_event.h>
52
53 #include <unistd.h>
54 #include <sys/syscall.h>
55 #include <poll.h>
56
57 #include "kselftest_harness.h"
58 #include "../clone3/clone3_selftests.h"
59
60 /* Attempt to de-conflict with the selftests tree. */
61 #ifndef SKIP
62 #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
63 #endif
64
65 #ifndef MIN
66 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
67 #endif
68
69 #ifndef PR_SET_PTRACER
70 # define PR_SET_PTRACER 0x59616d61
71 #endif
72
73 #ifndef noinline
74 #define noinline __attribute__((noinline))
75 #endif
76
77 #ifndef __nocf_check
78 #define __nocf_check __attribute__((nocf_check))
79 #endif
80
81 #ifndef __naked
82 #define __naked __attribute__((__naked__))
83 #endif
84
85 #ifndef PR_SET_NO_NEW_PRIVS
86 #define PR_SET_NO_NEW_PRIVS 38
87 #define PR_GET_NO_NEW_PRIVS 39
88 #endif
89
90 #ifndef PR_SECCOMP_EXT
91 #define PR_SECCOMP_EXT 43
92 #endif
93
94 #ifndef SECCOMP_EXT_ACT
95 #define SECCOMP_EXT_ACT 1
96 #endif
97
98 #ifndef SECCOMP_EXT_ACT_TSYNC
99 #define SECCOMP_EXT_ACT_TSYNC 1
100 #endif
101
102 #ifndef SECCOMP_MODE_STRICT
103 #define SECCOMP_MODE_STRICT 1
104 #endif
105
106 #ifndef SECCOMP_MODE_FILTER
107 #define SECCOMP_MODE_FILTER 2
108 #endif
109
110 #ifndef SECCOMP_RET_ALLOW
111 struct seccomp_data {
112 int nr;
113 __u32 arch;
114 __u64 instruction_pointer;
115 __u64 args[6];
116 };
117 #endif
118
119 #ifndef SECCOMP_RET_KILL_PROCESS
120 #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
121 #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
122 #endif
123 #ifndef SECCOMP_RET_KILL
124 #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
125 #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
126 #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
127 #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
128 #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
129 #endif
130 #ifndef SECCOMP_RET_LOG
131 #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
132 #endif
133
134 #ifndef __NR_seccomp
135 # if defined(__i386__)
136 # define __NR_seccomp 354
137 # elif defined(__x86_64__)
138 # define __NR_seccomp 317
139 # elif defined(__arm__)
140 # define __NR_seccomp 383
141 # elif defined(__aarch64__)
142 # define __NR_seccomp 277
143 # elif defined(__riscv)
144 # define __NR_seccomp 277
145 # elif defined(__csky__)
146 # define __NR_seccomp 277
147 # elif defined(__loongarch__)
148 # define __NR_seccomp 277
149 # elif defined(__hppa__)
150 # define __NR_seccomp 338
151 # elif defined(__powerpc__)
152 # define __NR_seccomp 358
153 # elif defined(__s390__)
154 # define __NR_seccomp 348
155 # elif defined(__xtensa__)
156 # define __NR_seccomp 337
157 # elif defined(__sh__)
158 # define __NR_seccomp 372
159 # elif defined(__mc68000__)
160 # define __NR_seccomp 380
161 # else
162 # warning "seccomp syscall number unknown for this architecture"
163 # define __NR_seccomp 0xffff
164 # endif
165 #endif
166
167 #ifndef __NR_uretprobe
168 # if defined(__x86_64__)
169 # define __NR_uretprobe 335
170 # endif
171 #endif
172
173 #ifndef __NR_uprobe
174 # if defined(__x86_64__)
175 # define __NR_uprobe 336
176 # endif
177 #endif
178
179 #ifndef SECCOMP_SET_MODE_STRICT
180 #define SECCOMP_SET_MODE_STRICT 0
181 #endif
182
183 #ifndef SECCOMP_SET_MODE_FILTER
184 #define SECCOMP_SET_MODE_FILTER 1
185 #endif
186
187 #ifndef SECCOMP_GET_ACTION_AVAIL
188 #define SECCOMP_GET_ACTION_AVAIL 2
189 #endif
190
191 #ifndef SECCOMP_GET_NOTIF_SIZES
192 #define SECCOMP_GET_NOTIF_SIZES 3
193 #endif
194
195 #ifndef SECCOMP_FILTER_FLAG_TSYNC
196 #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
197 #endif
198
199 #ifndef SECCOMP_FILTER_FLAG_LOG
200 #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
201 #endif
202
203 #ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
204 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
205 #endif
206
207 #ifndef PTRACE_SECCOMP_GET_METADATA
208 #define PTRACE_SECCOMP_GET_METADATA 0x420d
209
210 struct seccomp_metadata {
211 __u64 filter_off; /* Input: which filter */
212 __u64 flags; /* Output: filter's flags */
213 };
214 #endif
215
216 #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
217 #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
218 #endif
219
220 #ifndef SECCOMP_RET_USER_NOTIF
221 #define SECCOMP_RET_USER_NOTIF 0x7fc00000U
222
223 #define SECCOMP_IOC_MAGIC '!'
224 #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
225 #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
226 #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
227 #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
228
229 /* Flags for seccomp notification fd ioctl. */
230 #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
231 #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
232 struct seccomp_notif_resp)
233 #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)
234
235 struct seccomp_notif {
236 __u64 id;
237 __u32 pid;
238 __u32 flags;
239 struct seccomp_data data;
240 };
241
242 struct seccomp_notif_resp {
243 __u64 id;
244 __s64 val;
245 __s32 error;
246 __u32 flags;
247 };
248
249 struct seccomp_notif_sizes {
250 __u16 seccomp_notif;
251 __u16 seccomp_notif_resp;
252 __u16 seccomp_data;
253 };
254 #endif
255
256 #ifndef SECCOMP_IOCTL_NOTIF_ADDFD
257 /* On success, the return value is the remote process's added fd number */
258 #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \
259 struct seccomp_notif_addfd)
260
261 /* valid flags for seccomp_notif_addfd */
262 #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */
263
264 struct seccomp_notif_addfd {
265 __u64 id;
266 __u32 flags;
267 __u32 srcfd;
268 __u32 newfd;
269 __u32 newfd_flags;
270 };
271 #endif
272
273 #ifndef SECCOMP_ADDFD_FLAG_SEND
274 #define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */
275 #endif
276
277 struct seccomp_notif_addfd_small {
278 __u64 id;
279 char weird[4];
280 };
281 #define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \
282 SECCOMP_IOW(3, struct seccomp_notif_addfd_small)
283
284 struct seccomp_notif_addfd_big {
285 union {
286 struct seccomp_notif_addfd addfd;
287 char buf[sizeof(struct seccomp_notif_addfd) + 8];
288 };
289 };
290 #define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \
291 SECCOMP_IOWR(3, struct seccomp_notif_addfd_big)
292
293 #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
294 #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
295 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2
296 #endif
297
298 #ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
299 #define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
300 #endif
301
302 #ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
303 #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
304 #endif
305
306 #ifndef SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
307 #define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5)
308 #endif
309
310 #ifndef seccomp
seccomp(unsigned int op,unsigned int flags,void * args)311 int seccomp(unsigned int op, unsigned int flags, void *args)
312 {
313 errno = 0;
314 return syscall(__NR_seccomp, op, flags, args);
315 }
316 #endif
317
318 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
319 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
320 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
321 #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
322 #else
323 #error "wut? Unknown __BYTE_ORDER__?!"
324 #endif
325
326 #define SIBLING_EXIT_UNKILLED 0xbadbeef
327 #define SIBLING_EXIT_FAILURE 0xbadface
328 #define SIBLING_EXIT_NEWPRIVS 0xbadfeed
329
__filecmp(pid_t pid1,pid_t pid2,int fd1,int fd2)330 static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
331 {
332 #ifdef __NR_kcmp
333 errno = 0;
334 return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
335 #else
336 errno = ENOSYS;
337 return -1;
338 #endif
339 }
340
341 /* Have TH_LOG report actual location filecmp() is used. */
342 #define filecmp(pid1, pid2, fd1, fd2) ({ \
343 int _ret; \
344 \
345 _ret = __filecmp(pid1, pid2, fd1, fd2); \
346 if (_ret != 0) { \
347 if (_ret < 0 && errno == ENOSYS) { \
348 TH_LOG("kcmp() syscall missing (test is less accurate)");\
349 _ret = 0; \
350 } \
351 } \
352 _ret; })
353
TEST(kcmp)354 TEST(kcmp)
355 {
356 int ret;
357
358 ret = __filecmp(getpid(), getpid(), 1, 1);
359 EXPECT_EQ(ret, 0);
360 if (ret != 0 && errno == ENOSYS)
361 SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)");
362 }
363
TEST(mode_strict_support)364 TEST(mode_strict_support)
365 {
366 long ret;
367
368 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
369 ASSERT_EQ(0, ret) {
370 TH_LOG("Kernel does not support CONFIG_SECCOMP");
371 }
372 syscall(__NR_exit, 0);
373 }
374
TEST_SIGNAL(mode_strict_cannot_call_prctl,SIGKILL)375 TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
376 {
377 long ret;
378
379 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
380 ASSERT_EQ(0, ret) {
381 TH_LOG("Kernel does not support CONFIG_SECCOMP");
382 }
383 syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
384 NULL, NULL, NULL);
385 EXPECT_FALSE(true) {
386 TH_LOG("Unreachable!");
387 }
388 }
389
390 /* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)391 TEST(no_new_privs_support)
392 {
393 long ret;
394
395 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
396 EXPECT_EQ(0, ret) {
397 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
398 }
399 }
400
401 /* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)402 TEST(mode_filter_support)
403 {
404 long ret;
405
406 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
407 ASSERT_EQ(0, ret) {
408 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
409 }
410 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
411 EXPECT_EQ(-1, ret);
412 EXPECT_EQ(EFAULT, errno) {
413 TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
414 }
415 }
416
TEST(mode_filter_without_nnp)417 TEST(mode_filter_without_nnp)
418 {
419 struct sock_filter filter[] = {
420 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
421 };
422 struct sock_fprog prog = {
423 .len = (unsigned short)ARRAY_SIZE(filter),
424 .filter = filter,
425 };
426 long ret;
427 cap_t cap = cap_get_proc();
428 cap_flag_value_t is_cap_sys_admin = 0;
429
430 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
431 ASSERT_LE(0, ret) {
432 TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
433 }
434 errno = 0;
435 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
436 /* Succeeds with CAP_SYS_ADMIN, fails without */
437 cap_get_flag(cap, CAP_SYS_ADMIN, CAP_EFFECTIVE, &is_cap_sys_admin);
438 if (!is_cap_sys_admin) {
439 EXPECT_EQ(-1, ret);
440 EXPECT_EQ(EACCES, errno);
441 } else {
442 EXPECT_EQ(0, ret);
443 }
444 }
445
446 #define MAX_INSNS_PER_PATH 32768
447
TEST(filter_size_limits)448 TEST(filter_size_limits)
449 {
450 int i;
451 int count = BPF_MAXINSNS + 1;
452 struct sock_filter allow[] = {
453 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
454 };
455 struct sock_filter *filter;
456 struct sock_fprog prog = { };
457 long ret;
458
459 filter = calloc(count, sizeof(*filter));
460 ASSERT_NE(NULL, filter);
461
462 for (i = 0; i < count; i++)
463 filter[i] = allow[0];
464
465 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
466 ASSERT_EQ(0, ret);
467
468 prog.filter = filter;
469 prog.len = count;
470
471 /* Too many filter instructions in a single filter. */
472 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
473 ASSERT_NE(0, ret) {
474 TH_LOG("Installing %d insn filter was allowed", prog.len);
475 }
476
477 /* One less is okay, though. */
478 prog.len -= 1;
479 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
480 ASSERT_EQ(0, ret) {
481 TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
482 }
483 }
484
TEST(filter_chain_limits)485 TEST(filter_chain_limits)
486 {
487 int i;
488 int count = BPF_MAXINSNS;
489 struct sock_filter allow[] = {
490 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
491 };
492 struct sock_filter *filter;
493 struct sock_fprog prog = { };
494 long ret;
495
496 filter = calloc(count, sizeof(*filter));
497 ASSERT_NE(NULL, filter);
498
499 for (i = 0; i < count; i++)
500 filter[i] = allow[0];
501
502 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
503 ASSERT_EQ(0, ret);
504
505 prog.filter = filter;
506 prog.len = 1;
507
508 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
509 ASSERT_EQ(0, ret);
510
511 prog.len = count;
512
513 /* Too many total filter instructions. */
514 for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
515 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
516 if (ret != 0)
517 break;
518 }
519 ASSERT_NE(0, ret) {
520 TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
521 i, count, i * (count + 4));
522 }
523 }
524
TEST(mode_filter_cannot_move_to_strict)525 TEST(mode_filter_cannot_move_to_strict)
526 {
527 struct sock_filter filter[] = {
528 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
529 };
530 struct sock_fprog prog = {
531 .len = (unsigned short)ARRAY_SIZE(filter),
532 .filter = filter,
533 };
534 long ret;
535
536 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
537 ASSERT_EQ(0, ret);
538
539 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
540 ASSERT_EQ(0, ret);
541
542 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
543 EXPECT_EQ(-1, ret);
544 EXPECT_EQ(EINVAL, errno);
545 }
546
547
TEST(mode_filter_get_seccomp)548 TEST(mode_filter_get_seccomp)
549 {
550 struct sock_filter filter[] = {
551 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
552 };
553 struct sock_fprog prog = {
554 .len = (unsigned short)ARRAY_SIZE(filter),
555 .filter = filter,
556 };
557 long ret;
558
559 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
560 ASSERT_EQ(0, ret);
561
562 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
563 EXPECT_EQ(0, ret);
564
565 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
566 ASSERT_EQ(0, ret);
567
568 ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
569 EXPECT_EQ(2, ret);
570 }
571
572
TEST(ALLOW_all)573 TEST(ALLOW_all)
574 {
575 struct sock_filter filter[] = {
576 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
577 };
578 struct sock_fprog prog = {
579 .len = (unsigned short)ARRAY_SIZE(filter),
580 .filter = filter,
581 };
582 long ret;
583
584 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
585 ASSERT_EQ(0, ret);
586
587 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
588 ASSERT_EQ(0, ret);
589 }
590
TEST(empty_prog)591 TEST(empty_prog)
592 {
593 struct sock_filter filter[] = {
594 };
595 struct sock_fprog prog = {
596 .len = (unsigned short)ARRAY_SIZE(filter),
597 .filter = filter,
598 };
599 long ret;
600
601 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
602 ASSERT_EQ(0, ret);
603
604 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
605 EXPECT_EQ(-1, ret);
606 EXPECT_EQ(EINVAL, errno);
607 }
608
TEST(log_all)609 TEST(log_all)
610 {
611 struct sock_filter filter[] = {
612 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
613 };
614 struct sock_fprog prog = {
615 .len = (unsigned short)ARRAY_SIZE(filter),
616 .filter = filter,
617 };
618 long ret;
619 pid_t parent = getppid();
620
621 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
622 ASSERT_EQ(0, ret);
623
624 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
625 ASSERT_EQ(0, ret);
626
627 /* getppid() should succeed and be logged (no check for logging) */
628 EXPECT_EQ(parent, syscall(__NR_getppid));
629 }
630
TEST_SIGNAL(unknown_ret_is_kill_inside,SIGSYS)631 TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
632 {
633 struct sock_filter filter[] = {
634 BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
635 };
636 struct sock_fprog prog = {
637 .len = (unsigned short)ARRAY_SIZE(filter),
638 .filter = filter,
639 };
640 long ret;
641
642 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
643 ASSERT_EQ(0, ret);
644
645 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
646 ASSERT_EQ(0, ret);
647 EXPECT_EQ(0, syscall(__NR_getpid)) {
648 TH_LOG("getpid() shouldn't ever return");
649 }
650 }
651
652 /* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow,SIGSYS)653 TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
654 {
655 struct sock_filter filter[] = {
656 BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
657 };
658 struct sock_fprog prog = {
659 .len = (unsigned short)ARRAY_SIZE(filter),
660 .filter = filter,
661 };
662 long ret;
663
664 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
665 ASSERT_EQ(0, ret);
666
667 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
668 ASSERT_EQ(0, ret);
669 EXPECT_EQ(0, syscall(__NR_getpid)) {
670 TH_LOG("getpid() shouldn't ever return");
671 }
672 }
673
TEST_SIGNAL(KILL_all,SIGSYS)674 TEST_SIGNAL(KILL_all, SIGSYS)
675 {
676 struct sock_filter filter[] = {
677 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
678 };
679 struct sock_fprog prog = {
680 .len = (unsigned short)ARRAY_SIZE(filter),
681 .filter = filter,
682 };
683 long ret;
684
685 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
686 ASSERT_EQ(0, ret);
687
688 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
689 ASSERT_EQ(0, ret);
690 }
691
TEST_SIGNAL(KILL_one,SIGSYS)692 TEST_SIGNAL(KILL_one, SIGSYS)
693 {
694 struct sock_filter filter[] = {
695 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
696 offsetof(struct seccomp_data, nr)),
697 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
698 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
699 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
700 };
701 struct sock_fprog prog = {
702 .len = (unsigned short)ARRAY_SIZE(filter),
703 .filter = filter,
704 };
705 long ret;
706 pid_t parent = getppid();
707
708 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
709 ASSERT_EQ(0, ret);
710
711 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
712 ASSERT_EQ(0, ret);
713
714 EXPECT_EQ(parent, syscall(__NR_getppid));
715 /* getpid() should never return. */
716 EXPECT_EQ(0, syscall(__NR_getpid));
717 }
718
TEST_SIGNAL(KILL_one_arg_one,SIGSYS)719 TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
720 {
721 void *fatal_address;
722 struct sock_filter filter[] = {
723 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
724 offsetof(struct seccomp_data, nr)),
725 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
726 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
727 /* Only both with lower 32-bit for now. */
728 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
729 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
730 (unsigned long)&fatal_address, 0, 1),
731 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
732 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
733 };
734 struct sock_fprog prog = {
735 .len = (unsigned short)ARRAY_SIZE(filter),
736 .filter = filter,
737 };
738 long ret;
739 pid_t parent = getppid();
740 struct tms timebuf;
741 clock_t clock = times(&timebuf);
742
743 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
744 ASSERT_EQ(0, ret);
745
746 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
747 ASSERT_EQ(0, ret);
748
749 EXPECT_EQ(parent, syscall(__NR_getppid));
750 EXPECT_LE(clock, syscall(__NR_times, &timebuf));
751 /* times() should never return. */
752 EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
753 }
754
TEST_SIGNAL(KILL_one_arg_six,SIGSYS)755 TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
756 {
757 #ifndef __NR_mmap2
758 int sysno = __NR_mmap;
759 #else
760 int sysno = __NR_mmap2;
761 #endif
762 struct sock_filter filter[] = {
763 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
764 offsetof(struct seccomp_data, nr)),
765 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
766 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
767 /* Only both with lower 32-bit for now. */
768 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
769 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
770 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
771 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
772 };
773 struct sock_fprog prog = {
774 .len = (unsigned short)ARRAY_SIZE(filter),
775 .filter = filter,
776 };
777 long ret;
778 pid_t parent = getppid();
779 int fd;
780 void *map1, *map2;
781 int page_size = sysconf(_SC_PAGESIZE);
782
783 ASSERT_LT(0, page_size);
784
785 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
786 ASSERT_EQ(0, ret);
787
788 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
789 ASSERT_EQ(0, ret);
790
791 fd = open("/dev/zero", O_RDONLY);
792 ASSERT_NE(-1, fd);
793
794 EXPECT_EQ(parent, syscall(__NR_getppid));
795 map1 = (void *)syscall(sysno,
796 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
797 EXPECT_NE(MAP_FAILED, map1);
798 /* mmap2() should never return. */
799 map2 = (void *)syscall(sysno,
800 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
801 EXPECT_EQ(MAP_FAILED, map2);
802
803 /* The test failed, so clean up the resources. */
804 munmap(map1, page_size);
805 munmap(map2, page_size);
806 close(fd);
807 }
808
809 /* This is a thread task to die via seccomp filter violation. */
kill_thread(void * data)810 void *kill_thread(void *data)
811 {
812 bool die = (bool)data;
813
814 if (die) {
815 syscall(__NR_getpid);
816 return (void *)SIBLING_EXIT_FAILURE;
817 }
818
819 return (void *)SIBLING_EXIT_UNKILLED;
820 }
821
822 enum kill_t {
823 KILL_THREAD,
824 KILL_PROCESS,
825 RET_UNKNOWN
826 };
827
828 /* Prepare a thread that will kill itself or both of us. */
kill_thread_or_group(struct __test_metadata * _metadata,enum kill_t kill_how)829 void kill_thread_or_group(struct __test_metadata *_metadata,
830 enum kill_t kill_how)
831 {
832 pthread_t thread;
833 void *status;
834 /* Kill only when calling __NR_getpid. */
835 struct sock_filter filter_thread[] = {
836 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
837 offsetof(struct seccomp_data, nr)),
838 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
839 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
840 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
841 };
842 struct sock_fprog prog_thread = {
843 .len = (unsigned short)ARRAY_SIZE(filter_thread),
844 .filter = filter_thread,
845 };
846 int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAA;
847 struct sock_filter filter_process[] = {
848 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
849 offsetof(struct seccomp_data, nr)),
850 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
851 BPF_STMT(BPF_RET|BPF_K, kill),
852 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
853 };
854 struct sock_fprog prog_process = {
855 .len = (unsigned short)ARRAY_SIZE(filter_process),
856 .filter = filter_process,
857 };
858
859 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
860 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
861 }
862
863 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
864 kill_how == KILL_THREAD ? &prog_thread
865 : &prog_process));
866
867 /*
868 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
869 * flag cannot be downgraded by a new filter.
870 */
871 if (kill_how == KILL_PROCESS)
872 ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
873
874 /* Start a thread that will exit immediately. */
875 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
876 ASSERT_EQ(0, pthread_join(thread, &status));
877 ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
878
879 /* Start a thread that will die immediately. */
880 ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
881 ASSERT_EQ(0, pthread_join(thread, &status));
882 ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
883
884 /*
885 * If we get here, only the spawned thread died. Let the parent know
886 * the whole process didn't die (i.e. this thread, the spawner,
887 * stayed running).
888 */
889 exit(42);
890 }
891
TEST(KILL_thread)892 TEST(KILL_thread)
893 {
894 int status;
895 pid_t child_pid;
896
897 child_pid = fork();
898 ASSERT_LE(0, child_pid);
899 if (child_pid == 0) {
900 kill_thread_or_group(_metadata, KILL_THREAD);
901 _exit(38);
902 }
903
904 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
905
906 /* If only the thread was killed, we'll see exit 42. */
907 ASSERT_TRUE(WIFEXITED(status));
908 ASSERT_EQ(42, WEXITSTATUS(status));
909 }
910
TEST(KILL_process)911 TEST(KILL_process)
912 {
913 int status;
914 pid_t child_pid;
915
916 child_pid = fork();
917 ASSERT_LE(0, child_pid);
918 if (child_pid == 0) {
919 kill_thread_or_group(_metadata, KILL_PROCESS);
920 _exit(38);
921 }
922
923 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
924
925 /* If the entire process was killed, we'll see SIGSYS. */
926 ASSERT_TRUE(WIFSIGNALED(status));
927 ASSERT_EQ(SIGSYS, WTERMSIG(status));
928 }
929
TEST(KILL_unknown)930 TEST(KILL_unknown)
931 {
932 int status;
933 pid_t child_pid;
934
935 child_pid = fork();
936 ASSERT_LE(0, child_pid);
937 if (child_pid == 0) {
938 kill_thread_or_group(_metadata, RET_UNKNOWN);
939 _exit(38);
940 }
941
942 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
943
944 /* If the entire process was killed, we'll see SIGSYS. */
945 EXPECT_TRUE(WIFSIGNALED(status)) {
946 TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
947 }
948 ASSERT_EQ(SIGSYS, WTERMSIG(status));
949 }
950
951 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)952 TEST(arg_out_of_range)
953 {
954 struct sock_filter filter[] = {
955 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
956 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
957 };
958 struct sock_fprog prog = {
959 .len = (unsigned short)ARRAY_SIZE(filter),
960 .filter = filter,
961 };
962 long ret;
963
964 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
965 ASSERT_EQ(0, ret);
966
967 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
968 EXPECT_EQ(-1, ret);
969 EXPECT_EQ(EINVAL, errno);
970 }
971
972 #define ERRNO_FILTER(name, errno) \
973 struct sock_filter _read_filter_##name[] = { \
974 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
975 offsetof(struct seccomp_data, nr)), \
976 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
977 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
978 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
979 }; \
980 struct sock_fprog prog_##name = { \
981 .len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
982 .filter = _read_filter_##name, \
983 }
984
985 /* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)986 TEST(ERRNO_valid)
987 {
988 ERRNO_FILTER(valid, E2BIG);
989 long ret;
990 pid_t parent = getppid();
991
992 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
993 ASSERT_EQ(0, ret);
994
995 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
996 ASSERT_EQ(0, ret);
997
998 EXPECT_EQ(parent, syscall(__NR_getppid));
999 EXPECT_EQ(-1, read(-1, NULL, 0));
1000 EXPECT_EQ(E2BIG, errno);
1001 }
1002
1003 /* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)1004 TEST(ERRNO_zero)
1005 {
1006 ERRNO_FILTER(zero, 0);
1007 long ret;
1008 pid_t parent = getppid();
1009
1010 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1011 ASSERT_EQ(0, ret);
1012
1013 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
1014 ASSERT_EQ(0, ret);
1015
1016 EXPECT_EQ(parent, syscall(__NR_getppid));
1017 /* "errno" of 0 is ok. */
1018 EXPECT_EQ(0, read(-1, NULL, 0));
1019 }
1020
1021 /*
1022 * The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
1023 * This tests that the errno value gets capped correctly, fixed by
1024 * 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
1025 */
TEST(ERRNO_capped)1026 TEST(ERRNO_capped)
1027 {
1028 ERRNO_FILTER(capped, 4096);
1029 long ret;
1030 pid_t parent = getppid();
1031
1032 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1033 ASSERT_EQ(0, ret);
1034
1035 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
1036 ASSERT_EQ(0, ret);
1037
1038 EXPECT_EQ(parent, syscall(__NR_getppid));
1039 EXPECT_EQ(-1, read(-1, NULL, 0));
1040 EXPECT_EQ(4095, errno);
1041 }
1042
1043 /*
1044 * Filters are processed in reverse order: last applied is executed first.
1045 * Since only the SECCOMP_RET_ACTION mask is tested for return values, the
1046 * SECCOMP_RET_DATA mask results will follow the most recently applied
1047 * matching filter return (and not the lowest or highest value).
1048 */
TEST(ERRNO_order)1049 TEST(ERRNO_order)
1050 {
1051 ERRNO_FILTER(first, 11);
1052 ERRNO_FILTER(second, 13);
1053 ERRNO_FILTER(third, 12);
1054 long ret;
1055 pid_t parent = getppid();
1056
1057 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1058 ASSERT_EQ(0, ret);
1059
1060 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
1061 ASSERT_EQ(0, ret);
1062
1063 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
1064 ASSERT_EQ(0, ret);
1065
1066 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
1067 ASSERT_EQ(0, ret);
1068
1069 EXPECT_EQ(parent, syscall(__NR_getppid));
1070 EXPECT_EQ(-1, read(-1, NULL, 0));
1071 EXPECT_EQ(12, errno);
1072 }
1073
FIXTURE(TRAP)1074 FIXTURE(TRAP) {
1075 struct sock_fprog prog;
1076 };
1077
FIXTURE_SETUP(TRAP)1078 FIXTURE_SETUP(TRAP)
1079 {
1080 struct sock_filter filter[] = {
1081 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1082 offsetof(struct seccomp_data, nr)),
1083 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
1084 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1085 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1086 };
1087
1088 memset(&self->prog, 0, sizeof(self->prog));
1089 self->prog.filter = malloc(sizeof(filter));
1090 ASSERT_NE(NULL, self->prog.filter);
1091 memcpy(self->prog.filter, filter, sizeof(filter));
1092 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1093 }
1094
FIXTURE_TEARDOWN(TRAP)1095 FIXTURE_TEARDOWN(TRAP)
1096 {
1097 if (self->prog.filter)
1098 free(self->prog.filter);
1099 }
1100
TEST_F_SIGNAL(TRAP,dfl,SIGSYS)1101 TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
1102 {
1103 long ret;
1104
1105 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1106 ASSERT_EQ(0, ret);
1107
1108 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1109 ASSERT_EQ(0, ret);
1110 syscall(__NR_getpid);
1111 }
1112
1113 /* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP,ign,SIGSYS)1114 TEST_F_SIGNAL(TRAP, ign, SIGSYS)
1115 {
1116 long ret;
1117
1118 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1119 ASSERT_EQ(0, ret);
1120
1121 signal(SIGSYS, SIG_IGN);
1122
1123 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1124 ASSERT_EQ(0, ret);
1125 syscall(__NR_getpid);
1126 }
1127
1128 static siginfo_t TRAP_info;
1129 static volatile int TRAP_nr;
TRAP_action(int nr,siginfo_t * info,void * void_context)1130 static void TRAP_action(int nr, siginfo_t *info, void *void_context)
1131 {
1132 memcpy(&TRAP_info, info, sizeof(TRAP_info));
1133 TRAP_nr = nr;
1134 }
1135
TEST_F(TRAP,handler)1136 TEST_F(TRAP, handler)
1137 {
1138 int ret, test;
1139 struct sigaction act;
1140 sigset_t mask;
1141
1142 memset(&act, 0, sizeof(act));
1143 sigemptyset(&mask);
1144 sigaddset(&mask, SIGSYS);
1145
1146 act.sa_sigaction = &TRAP_action;
1147 act.sa_flags = SA_SIGINFO;
1148 ret = sigaction(SIGSYS, &act, NULL);
1149 ASSERT_EQ(0, ret) {
1150 TH_LOG("sigaction failed");
1151 }
1152 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
1153 ASSERT_EQ(0, ret) {
1154 TH_LOG("sigprocmask failed");
1155 }
1156
1157 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1158 ASSERT_EQ(0, ret);
1159 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
1160 ASSERT_EQ(0, ret);
1161 TRAP_nr = 0;
1162 memset(&TRAP_info, 0, sizeof(TRAP_info));
1163 /* Expect the registers to be rolled back. (nr = error) may vary
1164 * based on arch. */
1165 ret = syscall(__NR_getpid);
1166 /* Silence gcc warning about volatile. */
1167 test = TRAP_nr;
1168 EXPECT_EQ(SIGSYS, test);
1169 struct local_sigsys {
1170 void *_call_addr; /* calling user insn */
1171 int _syscall; /* triggering system call number */
1172 unsigned int _arch; /* AUDIT_ARCH_* of syscall */
1173 } *sigsys = (struct local_sigsys *)
1174 #ifdef si_syscall
1175 &(TRAP_info.si_call_addr);
1176 #else
1177 &TRAP_info.si_pid;
1178 #endif
1179 EXPECT_EQ(__NR_getpid, sigsys->_syscall);
1180 /* Make sure arch is non-zero. */
1181 EXPECT_NE(0, sigsys->_arch);
1182 EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
1183 }
1184
FIXTURE(precedence)1185 FIXTURE(precedence) {
1186 struct sock_fprog allow;
1187 struct sock_fprog log;
1188 struct sock_fprog trace;
1189 struct sock_fprog error;
1190 struct sock_fprog trap;
1191 struct sock_fprog kill;
1192 };
1193
FIXTURE_SETUP(precedence)1194 FIXTURE_SETUP(precedence)
1195 {
1196 struct sock_filter allow_insns[] = {
1197 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1198 };
1199 struct sock_filter log_insns[] = {
1200 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1201 offsetof(struct seccomp_data, nr)),
1202 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1203 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1204 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
1205 };
1206 struct sock_filter trace_insns[] = {
1207 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1208 offsetof(struct seccomp_data, nr)),
1209 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1210 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1211 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
1212 };
1213 struct sock_filter error_insns[] = {
1214 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1215 offsetof(struct seccomp_data, nr)),
1216 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1217 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1218 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
1219 };
1220 struct sock_filter trap_insns[] = {
1221 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1222 offsetof(struct seccomp_data, nr)),
1223 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1224 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1225 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
1226 };
1227 struct sock_filter kill_insns[] = {
1228 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1229 offsetof(struct seccomp_data, nr)),
1230 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
1231 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1232 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
1233 };
1234
1235 memset(self, 0, sizeof(*self));
1236 #define FILTER_ALLOC(_x) \
1237 self->_x.filter = malloc(sizeof(_x##_insns)); \
1238 ASSERT_NE(NULL, self->_x.filter); \
1239 memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
1240 self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
1241 FILTER_ALLOC(allow);
1242 FILTER_ALLOC(log);
1243 FILTER_ALLOC(trace);
1244 FILTER_ALLOC(error);
1245 FILTER_ALLOC(trap);
1246 FILTER_ALLOC(kill);
1247 }
1248
FIXTURE_TEARDOWN(precedence)1249 FIXTURE_TEARDOWN(precedence)
1250 {
1251 #define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
1252 FILTER_FREE(allow);
1253 FILTER_FREE(log);
1254 FILTER_FREE(trace);
1255 FILTER_FREE(error);
1256 FILTER_FREE(trap);
1257 FILTER_FREE(kill);
1258 }
1259
TEST_F(precedence,allow_ok)1260 TEST_F(precedence, allow_ok)
1261 {
1262 pid_t parent, res = 0;
1263 long ret;
1264
1265 parent = getppid();
1266 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1267 ASSERT_EQ(0, ret);
1268
1269 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1270 ASSERT_EQ(0, ret);
1271 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1272 ASSERT_EQ(0, ret);
1273 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1274 ASSERT_EQ(0, ret);
1275 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1276 ASSERT_EQ(0, ret);
1277 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1278 ASSERT_EQ(0, ret);
1279 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1280 ASSERT_EQ(0, ret);
1281 /* Should work just fine. */
1282 res = syscall(__NR_getppid);
1283 EXPECT_EQ(parent, res);
1284 }
1285
TEST_F_SIGNAL(precedence,kill_is_highest,SIGSYS)1286 TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
1287 {
1288 pid_t parent, res = 0;
1289 long ret;
1290
1291 parent = getppid();
1292 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1293 ASSERT_EQ(0, ret);
1294
1295 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1296 ASSERT_EQ(0, ret);
1297 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1298 ASSERT_EQ(0, ret);
1299 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1300 ASSERT_EQ(0, ret);
1301 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1302 ASSERT_EQ(0, ret);
1303 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1304 ASSERT_EQ(0, ret);
1305 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1306 ASSERT_EQ(0, ret);
1307 /* Should work just fine. */
1308 res = syscall(__NR_getppid);
1309 EXPECT_EQ(parent, res);
1310 /* getpid() should never return. */
1311 res = syscall(__NR_getpid);
1312 EXPECT_EQ(0, res);
1313 }
1314
TEST_F_SIGNAL(precedence,kill_is_highest_in_any_order,SIGSYS)1315 TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
1316 {
1317 pid_t parent;
1318 long ret;
1319
1320 parent = getppid();
1321 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1322 ASSERT_EQ(0, ret);
1323
1324 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1325 ASSERT_EQ(0, ret);
1326 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
1327 ASSERT_EQ(0, ret);
1328 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1329 ASSERT_EQ(0, ret);
1330 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1331 ASSERT_EQ(0, ret);
1332 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1333 ASSERT_EQ(0, ret);
1334 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1335 ASSERT_EQ(0, ret);
1336 /* Should work just fine. */
1337 EXPECT_EQ(parent, syscall(__NR_getppid));
1338 /* getpid() should never return. */
1339 EXPECT_EQ(0, syscall(__NR_getpid));
1340 }
1341
TEST_F_SIGNAL(precedence,trap_is_second,SIGSYS)1342 TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
1343 {
1344 pid_t parent;
1345 long ret;
1346
1347 parent = getppid();
1348 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1349 ASSERT_EQ(0, ret);
1350
1351 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1352 ASSERT_EQ(0, ret);
1353 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1354 ASSERT_EQ(0, ret);
1355 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1356 ASSERT_EQ(0, ret);
1357 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1358 ASSERT_EQ(0, ret);
1359 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1360 ASSERT_EQ(0, ret);
1361 /* Should work just fine. */
1362 EXPECT_EQ(parent, syscall(__NR_getppid));
1363 /* getpid() should never return. */
1364 EXPECT_EQ(0, syscall(__NR_getpid));
1365 }
1366
TEST_F_SIGNAL(precedence,trap_is_second_in_any_order,SIGSYS)1367 TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
1368 {
1369 pid_t parent;
1370 long ret;
1371
1372 parent = getppid();
1373 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1374 ASSERT_EQ(0, ret);
1375
1376 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1377 ASSERT_EQ(0, ret);
1378 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
1379 ASSERT_EQ(0, ret);
1380 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1381 ASSERT_EQ(0, ret);
1382 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1383 ASSERT_EQ(0, ret);
1384 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1385 ASSERT_EQ(0, ret);
1386 /* Should work just fine. */
1387 EXPECT_EQ(parent, syscall(__NR_getppid));
1388 /* getpid() should never return. */
1389 EXPECT_EQ(0, syscall(__NR_getpid));
1390 }
1391
TEST_F(precedence,errno_is_third)1392 TEST_F(precedence, errno_is_third)
1393 {
1394 pid_t parent;
1395 long ret;
1396
1397 parent = getppid();
1398 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1399 ASSERT_EQ(0, ret);
1400
1401 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1402 ASSERT_EQ(0, ret);
1403 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1404 ASSERT_EQ(0, ret);
1405 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1406 ASSERT_EQ(0, ret);
1407 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1408 ASSERT_EQ(0, ret);
1409 /* Should work just fine. */
1410 EXPECT_EQ(parent, syscall(__NR_getppid));
1411 EXPECT_EQ(0, syscall(__NR_getpid));
1412 }
1413
TEST_F(precedence,errno_is_third_in_any_order)1414 TEST_F(precedence, errno_is_third_in_any_order)
1415 {
1416 pid_t parent;
1417 long ret;
1418
1419 parent = getppid();
1420 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1421 ASSERT_EQ(0, ret);
1422
1423 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1424 ASSERT_EQ(0, ret);
1425 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
1426 ASSERT_EQ(0, ret);
1427 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1428 ASSERT_EQ(0, ret);
1429 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1430 ASSERT_EQ(0, ret);
1431 /* Should work just fine. */
1432 EXPECT_EQ(parent, syscall(__NR_getppid));
1433 EXPECT_EQ(0, syscall(__NR_getpid));
1434 }
1435
TEST_F(precedence,trace_is_fourth)1436 TEST_F(precedence, trace_is_fourth)
1437 {
1438 pid_t parent;
1439 long ret;
1440
1441 parent = getppid();
1442 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1443 ASSERT_EQ(0, ret);
1444
1445 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1446 ASSERT_EQ(0, ret);
1447 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1448 ASSERT_EQ(0, ret);
1449 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1450 ASSERT_EQ(0, ret);
1451 /* Should work just fine. */
1452 EXPECT_EQ(parent, syscall(__NR_getppid));
1453 /* No ptracer */
1454 EXPECT_EQ(-1, syscall(__NR_getpid));
1455 }
1456
TEST_F(precedence,trace_is_fourth_in_any_order)1457 TEST_F(precedence, trace_is_fourth_in_any_order)
1458 {
1459 pid_t parent;
1460 long ret;
1461
1462 parent = getppid();
1463 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1464 ASSERT_EQ(0, ret);
1465
1466 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
1467 ASSERT_EQ(0, ret);
1468 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1469 ASSERT_EQ(0, ret);
1470 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1471 ASSERT_EQ(0, ret);
1472 /* Should work just fine. */
1473 EXPECT_EQ(parent, syscall(__NR_getppid));
1474 /* No ptracer */
1475 EXPECT_EQ(-1, syscall(__NR_getpid));
1476 }
1477
TEST_F(precedence,log_is_fifth)1478 TEST_F(precedence, log_is_fifth)
1479 {
1480 pid_t mypid, parent;
1481 long ret;
1482
1483 mypid = getpid();
1484 parent = getppid();
1485 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1486 ASSERT_EQ(0, ret);
1487
1488 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1489 ASSERT_EQ(0, ret);
1490 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1491 ASSERT_EQ(0, ret);
1492 /* Should work just fine. */
1493 EXPECT_EQ(parent, syscall(__NR_getppid));
1494 /* Should also work just fine */
1495 EXPECT_EQ(mypid, syscall(__NR_getpid));
1496 }
1497
TEST_F(precedence,log_is_fifth_in_any_order)1498 TEST_F(precedence, log_is_fifth_in_any_order)
1499 {
1500 pid_t mypid, parent;
1501 long ret;
1502
1503 mypid = getpid();
1504 parent = getppid();
1505 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1506 ASSERT_EQ(0, ret);
1507
1508 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
1509 ASSERT_EQ(0, ret);
1510 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
1511 ASSERT_EQ(0, ret);
1512 /* Should work just fine. */
1513 EXPECT_EQ(parent, syscall(__NR_getppid));
1514 /* Should also work just fine */
1515 EXPECT_EQ(mypid, syscall(__NR_getpid));
1516 }
1517
1518 #ifndef PTRACE_O_TRACESECCOMP
1519 #define PTRACE_O_TRACESECCOMP 0x00000080
1520 #endif
1521
1522 /* Catch the Ubuntu 12.04 value error. */
1523 #if PTRACE_EVENT_SECCOMP != 7
1524 #undef PTRACE_EVENT_SECCOMP
1525 #endif
1526
1527 #ifndef PTRACE_EVENT_SECCOMP
1528 #define PTRACE_EVENT_SECCOMP 7
1529 #endif
1530
1531 #define PTRACE_EVENT_MASK(status) ((status) >> 16)
1532 bool tracer_running;
tracer_stop(int sig)1533 void tracer_stop(int sig)
1534 {
1535 tracer_running = false;
1536 }
1537
1538 typedef void tracer_func_t(struct __test_metadata *_metadata,
1539 pid_t tracee, int status, void *args);
1540
start_tracer(struct __test_metadata * _metadata,int fd,pid_t tracee,tracer_func_t tracer_func,void * args,bool ptrace_syscall)1541 void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
1542 tracer_func_t tracer_func, void *args, bool ptrace_syscall)
1543 {
1544 int ret = -1;
1545 struct sigaction action = {
1546 .sa_handler = tracer_stop,
1547 };
1548
1549 /* Allow external shutdown. */
1550 tracer_running = true;
1551 ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
1552
1553 errno = 0;
1554 while (ret == -1 && errno != EINVAL)
1555 ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
1556 ASSERT_EQ(0, ret) {
1557 kill(tracee, SIGKILL);
1558 }
1559 /* Wait for attach stop */
1560 wait(NULL);
1561
1562 ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
1563 PTRACE_O_TRACESYSGOOD :
1564 PTRACE_O_TRACESECCOMP);
1565 ASSERT_EQ(0, ret) {
1566 TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
1567 kill(tracee, SIGKILL);
1568 }
1569 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1570 tracee, NULL, 0);
1571 ASSERT_EQ(0, ret);
1572
1573 /* Unblock the tracee */
1574 ASSERT_EQ(1, write(fd, "A", 1));
1575 ASSERT_EQ(0, close(fd));
1576
1577 /* Run until we're shut down. Must assert to stop execution. */
1578 while (tracer_running) {
1579 int status;
1580
1581 if (wait(&status) != tracee)
1582 continue;
1583
1584 if (WIFSIGNALED(status)) {
1585 /* Child caught a fatal signal. */
1586 return;
1587 }
1588 if (WIFEXITED(status)) {
1589 /* Child exited with code. */
1590 return;
1591 }
1592
1593 /* Check if we got an expected event. */
1594 ASSERT_EQ(WIFCONTINUED(status), false);
1595 ASSERT_EQ(WIFSTOPPED(status), true);
1596 ASSERT_EQ(WSTOPSIG(status) & SIGTRAP, SIGTRAP) {
1597 TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
1598 }
1599
1600 tracer_func(_metadata, tracee, status, args);
1601
1602 ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
1603 tracee, NULL, 0);
1604 ASSERT_EQ(0, ret);
1605 }
1606 /* Directly report the status of our test harness results. */
1607 syscall(__NR_exit, _metadata->exit_code);
1608 }
1609
1610 /* Common tracer setup/teardown functions. */
cont_handler(int num)1611 void cont_handler(int num)
1612 { }
setup_trace_fixture(struct __test_metadata * _metadata,tracer_func_t func,void * args,bool ptrace_syscall)1613 pid_t setup_trace_fixture(struct __test_metadata *_metadata,
1614 tracer_func_t func, void *args, bool ptrace_syscall)
1615 {
1616 char sync;
1617 int pipefd[2];
1618 pid_t tracer_pid;
1619 pid_t tracee = getpid();
1620
1621 /* Setup a pipe for clean synchronization. */
1622 ASSERT_EQ(0, pipe(pipefd));
1623
1624 /* Fork a child which we'll promote to tracer */
1625 tracer_pid = fork();
1626 ASSERT_LE(0, tracer_pid);
1627 signal(SIGALRM, cont_handler);
1628 if (tracer_pid == 0) {
1629 close(pipefd[0]);
1630 start_tracer(_metadata, pipefd[1], tracee, func, args,
1631 ptrace_syscall);
1632 syscall(__NR_exit, 0);
1633 }
1634 close(pipefd[1]);
1635 prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
1636 read(pipefd[0], &sync, 1);
1637 close(pipefd[0]);
1638
1639 return tracer_pid;
1640 }
1641
teardown_trace_fixture(struct __test_metadata * _metadata,pid_t tracer)1642 void teardown_trace_fixture(struct __test_metadata *_metadata,
1643 pid_t tracer)
1644 {
1645 if (tracer) {
1646 int status;
1647 ASSERT_EQ(0, kill(tracer, SIGUSR1));
1648 ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
1649 }
1650 }
1651
1652 /* "poke" tracer arguments and function. */
1653 struct tracer_args_poke_t {
1654 unsigned long poke_addr;
1655 };
1656
tracer_poke(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)1657 void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
1658 void *args)
1659 {
1660 int ret;
1661 unsigned long msg;
1662 struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
1663
1664 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
1665 EXPECT_EQ(0, ret);
1666 /* If this fails, don't try to recover. */
1667 ASSERT_EQ(0x1001, msg) {
1668 kill(tracee, SIGKILL);
1669 }
1670 /*
1671 * Poke in the message.
1672 * Registers are not touched to try to keep this relatively arch
1673 * agnostic.
1674 */
1675 ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
1676 EXPECT_EQ(0, ret);
1677 }
1678
FIXTURE(TRACE_poke)1679 FIXTURE(TRACE_poke) {
1680 struct sock_fprog prog;
1681 pid_t tracer;
1682 long poked;
1683 struct tracer_args_poke_t tracer_args;
1684 };
1685
FIXTURE_SETUP(TRACE_poke)1686 FIXTURE_SETUP(TRACE_poke)
1687 {
1688 struct sock_filter filter[] = {
1689 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
1690 offsetof(struct seccomp_data, nr)),
1691 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
1692 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
1693 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
1694 };
1695
1696 self->poked = 0;
1697 memset(&self->prog, 0, sizeof(self->prog));
1698 self->prog.filter = malloc(sizeof(filter));
1699 ASSERT_NE(NULL, self->prog.filter);
1700 memcpy(self->prog.filter, filter, sizeof(filter));
1701 self->prog.len = (unsigned short)ARRAY_SIZE(filter);
1702
1703 /* Set up tracer args. */
1704 self->tracer_args.poke_addr = (unsigned long)&self->poked;
1705
1706 /* Launch tracer. */
1707 self->tracer = setup_trace_fixture(_metadata, tracer_poke,
1708 &self->tracer_args, false);
1709 }
1710
FIXTURE_TEARDOWN(TRACE_poke)1711 FIXTURE_TEARDOWN(TRACE_poke)
1712 {
1713 teardown_trace_fixture(_metadata, self->tracer);
1714 if (self->prog.filter)
1715 free(self->prog.filter);
1716 }
1717
TEST_F(TRACE_poke,read_has_side_effects)1718 TEST_F(TRACE_poke, read_has_side_effects)
1719 {
1720 ssize_t ret;
1721
1722 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1723 ASSERT_EQ(0, ret);
1724
1725 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1726 ASSERT_EQ(0, ret);
1727
1728 EXPECT_EQ(0, self->poked);
1729 ret = read(-1, NULL, 0);
1730 EXPECT_EQ(-1, ret);
1731 EXPECT_EQ(0x1001, self->poked);
1732 }
1733
TEST_F(TRACE_poke,getpid_runs_normally)1734 TEST_F(TRACE_poke, getpid_runs_normally)
1735 {
1736 long ret;
1737
1738 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
1739 ASSERT_EQ(0, ret);
1740
1741 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
1742 ASSERT_EQ(0, ret);
1743
1744 EXPECT_EQ(0, self->poked);
1745 EXPECT_NE(0, syscall(__NR_getpid));
1746 EXPECT_EQ(0, self->poked);
1747 }
1748
1749 #if defined(__x86_64__)
1750 # define ARCH_REGS struct user_regs_struct
1751 # define SYSCALL_NUM(_regs) (_regs).orig_rax
1752 # define SYSCALL_RET(_regs) (_regs).rax
1753 #elif defined(__i386__)
1754 # define ARCH_REGS struct user_regs_struct
1755 # define SYSCALL_NUM(_regs) (_regs).orig_eax
1756 # define SYSCALL_RET(_regs) (_regs).eax
1757 #elif defined(__arm__)
1758 # define ARCH_REGS struct pt_regs
1759 # define SYSCALL_NUM(_regs) (_regs).ARM_r7
1760 # ifndef PTRACE_SET_SYSCALL
1761 # define PTRACE_SET_SYSCALL 23
1762 # endif
1763 # define SYSCALL_NUM_SET(_regs, _nr) \
1764 EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
1765 # define SYSCALL_RET(_regs) (_regs).ARM_r0
1766 #elif defined(__aarch64__)
1767 # define ARCH_REGS struct user_pt_regs
1768 # define SYSCALL_NUM(_regs) (_regs).regs[8]
1769 # ifndef NT_ARM_SYSTEM_CALL
1770 # define NT_ARM_SYSTEM_CALL 0x404
1771 # endif
1772 # define SYSCALL_NUM_SET(_regs, _nr) \
1773 do { \
1774 struct iovec __v; \
1775 typeof(_nr) __nr = (_nr); \
1776 __v.iov_base = &__nr; \
1777 __v.iov_len = sizeof(__nr); \
1778 EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \
1779 NT_ARM_SYSTEM_CALL, &__v)); \
1780 } while (0)
1781 # define SYSCALL_RET(_regs) (_regs).regs[0]
1782 #elif defined(__loongarch__)
1783 # define ARCH_REGS struct user_pt_regs
1784 # define SYSCALL_NUM(_regs) (_regs).regs[11]
1785 # define SYSCALL_RET(_regs) (_regs).regs[4]
1786 #elif defined(__riscv) && __riscv_xlen == 64
1787 # define ARCH_REGS struct user_regs_struct
1788 # define SYSCALL_NUM(_regs) (_regs).a7
1789 # define SYSCALL_RET(_regs) (_regs).a0
1790 #elif defined(__csky__)
1791 # define ARCH_REGS struct pt_regs
1792 # if defined(__CSKYABIV2__)
1793 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1794 # else
1795 # define SYSCALL_NUM(_regs) (_regs).regs[9]
1796 # endif
1797 # define SYSCALL_RET(_regs) (_regs).a0
1798 #elif defined(__hppa__)
1799 # define ARCH_REGS struct user_regs_struct
1800 # define SYSCALL_NUM(_regs) (_regs).gr[20]
1801 # define SYSCALL_RET(_regs) (_regs).gr[28]
1802 #elif defined(__powerpc__)
1803 # define ARCH_REGS struct pt_regs
1804 # define SYSCALL_NUM(_regs) (_regs).gpr[0]
1805 # define SYSCALL_RET(_regs) (_regs).gpr[3]
1806 # define SYSCALL_RET_SET(_regs, _val) \
1807 do { \
1808 typeof(_val) _result = (_val); \
1809 if ((_regs.trap & 0xfff0) == 0x3000) { \
1810 /* \
1811 * scv 0 system call uses -ve result \
1812 * for error, so no need to adjust. \
1813 */ \
1814 SYSCALL_RET(_regs) = _result; \
1815 } else { \
1816 /* \
1817 * A syscall error is signaled by the \
1818 * CR0 SO bit and the code is stored as \
1819 * a positive value. \
1820 */ \
1821 if (_result < 0) { \
1822 SYSCALL_RET(_regs) = -_result; \
1823 (_regs).ccr |= 0x10000000; \
1824 } else { \
1825 SYSCALL_RET(_regs) = _result; \
1826 (_regs).ccr &= ~0x10000000; \
1827 } \
1828 } \
1829 } while (0)
1830 # define SYSCALL_RET_SET_ON_PTRACE_EXIT
1831 #elif defined(__s390__)
1832 # define ARCH_REGS s390_regs
1833 # define SYSCALL_NUM(_regs) (_regs).gprs[2]
1834 # define SYSCALL_RET_SET(_regs, _val) \
1835 TH_LOG("Can't modify syscall return on this architecture")
1836 #elif defined(__mips__)
1837 # include <asm/unistd_nr_n32.h>
1838 # include <asm/unistd_nr_n64.h>
1839 # include <asm/unistd_nr_o32.h>
1840 # define ARCH_REGS struct pt_regs
1841 # define SYSCALL_NUM(_regs) \
1842 ({ \
1843 typeof((_regs).regs[2]) _nr; \
1844 if ((_regs).regs[2] == __NR_O32_Linux) \
1845 _nr = (_regs).regs[4]; \
1846 else \
1847 _nr = (_regs).regs[2]; \
1848 _nr; \
1849 })
1850 # define SYSCALL_NUM_SET(_regs, _nr) \
1851 do { \
1852 if ((_regs).regs[2] == __NR_O32_Linux) \
1853 (_regs).regs[4] = _nr; \
1854 else \
1855 (_regs).regs[2] = _nr; \
1856 } while (0)
1857 # define SYSCALL_RET_SET(_regs, _val) \
1858 TH_LOG("Can't modify syscall return on this architecture")
1859 #elif defined(__xtensa__)
1860 # define ARCH_REGS struct user_pt_regs
1861 # define SYSCALL_NUM(_regs) (_regs).syscall
1862 /*
1863 * On xtensa syscall return value is in the register
1864 * a2 of the current window which is not fixed.
1865 */
1866 #define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2]
1867 #elif defined(__sh__)
1868 # define ARCH_REGS struct pt_regs
1869 # define SYSCALL_NUM(_regs) (_regs).regs[3]
1870 # define SYSCALL_RET(_regs) (_regs).regs[0]
1871 #elif defined(__mc68000__)
1872 # define ARCH_REGS struct user_regs_struct
1873 # define SYSCALL_NUM(_regs) (_regs).orig_d0
1874 # define SYSCALL_RET(_regs) (_regs).d0
1875 #else
1876 # error "Do not know how to find your architecture's registers and syscalls"
1877 #endif
1878
1879 /*
1880 * Most architectures can change the syscall by just updating the
1881 * associated register. This is the default if not defined above.
1882 */
1883 #ifndef SYSCALL_NUM_SET
1884 # define SYSCALL_NUM_SET(_regs, _nr) \
1885 do { \
1886 SYSCALL_NUM(_regs) = (_nr); \
1887 } while (0)
1888 #endif
1889 /*
1890 * Most architectures can change the syscall return value by just
1891 * writing to the SYSCALL_RET register. This is the default if not
1892 * defined above. If an architecture cannot set the return value
1893 * (for example when the syscall and return value register is
1894 * shared), report it with TH_LOG() in an arch-specific definition
1895 * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
1896 */
1897 #if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
1898 # error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
1899 #endif
1900 #ifndef SYSCALL_RET_SET
1901 # define SYSCALL_RET_SET(_regs, _val) \
1902 do { \
1903 SYSCALL_RET(_regs) = (_val); \
1904 } while (0)
1905 #endif
1906
1907 /* When the syscall return can't be changed, stub out the tests for it. */
1908 #ifndef SYSCALL_RET
1909 # define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
1910 #else
1911 # define EXPECT_SYSCALL_RETURN(val, action) \
1912 do { \
1913 errno = 0; \
1914 if (val < 0) { \
1915 EXPECT_EQ(-1, action); \
1916 EXPECT_EQ(-(val), errno); \
1917 } else { \
1918 EXPECT_EQ(val, action); \
1919 } \
1920 } while (0)
1921 #endif
1922
1923 /*
1924 * Some architectures (e.g. powerpc) can only set syscall
1925 * return values on syscall exit during ptrace.
1926 */
1927 const bool ptrace_entry_set_syscall_nr = true;
1928 const bool ptrace_entry_set_syscall_ret =
1929 #ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
1930 true;
1931 #else
1932 false;
1933 #endif
1934
1935 /*
1936 * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
1937 * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
1938 */
1939 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__) || defined(__mc68000__)
1940 # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
1941 # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
1942 #else
1943 # define ARCH_GETREGS(_regs) ({ \
1944 struct iovec __v; \
1945 __v.iov_base = &(_regs); \
1946 __v.iov_len = sizeof(_regs); \
1947 ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \
1948 })
1949 # define ARCH_SETREGS(_regs) ({ \
1950 struct iovec __v; \
1951 __v.iov_base = &(_regs); \
1952 __v.iov_len = sizeof(_regs); \
1953 ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \
1954 })
1955 #endif
1956
1957 /* Architecture-specific syscall fetching routine. */
get_syscall(struct __test_metadata * _metadata,pid_t tracee)1958 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
1959 {
1960 ARCH_REGS regs;
1961
1962 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1963 return -1;
1964 }
1965
1966 return SYSCALL_NUM(regs);
1967 }
1968
1969 /* Architecture-specific syscall changing routine. */
__change_syscall(struct __test_metadata * _metadata,pid_t tracee,long * syscall,long * ret)1970 void __change_syscall(struct __test_metadata *_metadata,
1971 pid_t tracee, long *syscall, long *ret)
1972 {
1973 ARCH_REGS orig, regs;
1974
1975 /* Do not get/set registers if we have nothing to do. */
1976 if (!syscall && !ret)
1977 return;
1978
1979 EXPECT_EQ(0, ARCH_GETREGS(regs)) {
1980 return;
1981 }
1982 orig = regs;
1983
1984 if (syscall)
1985 SYSCALL_NUM_SET(regs, *syscall);
1986
1987 if (ret)
1988 SYSCALL_RET_SET(regs, *ret);
1989
1990 /* Flush any register changes made. */
1991 if (memcmp(&orig, ®s, sizeof(orig)) != 0)
1992 EXPECT_EQ(0, ARCH_SETREGS(regs));
1993 }
1994
1995 /* Change only syscall number. */
change_syscall_nr(struct __test_metadata * _metadata,pid_t tracee,long syscall)1996 void change_syscall_nr(struct __test_metadata *_metadata,
1997 pid_t tracee, long syscall)
1998 {
1999 __change_syscall(_metadata, tracee, &syscall, NULL);
2000 }
2001
2002 /* Change syscall return value (and set syscall number to -1). */
change_syscall_ret(struct __test_metadata * _metadata,pid_t tracee,long ret)2003 void change_syscall_ret(struct __test_metadata *_metadata,
2004 pid_t tracee, long ret)
2005 {
2006 long syscall = -1;
2007
2008 __change_syscall(_metadata, tracee, &syscall, &ret);
2009 }
2010
tracer_seccomp(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)2011 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
2012 int status, void *args)
2013 {
2014 int ret;
2015 unsigned long msg;
2016
2017 EXPECT_EQ(PTRACE_EVENT_MASK(status), PTRACE_EVENT_SECCOMP) {
2018 TH_LOG("Unexpected ptrace event: %d", PTRACE_EVENT_MASK(status));
2019 return;
2020 }
2021
2022 /* Make sure we got the right message. */
2023 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
2024 EXPECT_EQ(0, ret);
2025
2026 /* Validate and take action on expected syscalls. */
2027 switch (msg) {
2028 case 0x1002:
2029 /* change getpid to getppid. */
2030 EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
2031 change_syscall_nr(_metadata, tracee, __NR_getppid);
2032 break;
2033 case 0x1003:
2034 /* skip gettid with valid return code. */
2035 EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
2036 change_syscall_ret(_metadata, tracee, 45000);
2037 break;
2038 case 0x1004:
2039 /* skip openat with error. */
2040 EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
2041 change_syscall_ret(_metadata, tracee, -ESRCH);
2042 break;
2043 case 0x1005:
2044 /* do nothing (allow getppid) */
2045 EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
2046 break;
2047 default:
2048 EXPECT_EQ(0, msg) {
2049 TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
2050 kill(tracee, SIGKILL);
2051 }
2052 }
2053
2054 }
2055
FIXTURE(TRACE_syscall)2056 FIXTURE(TRACE_syscall) {
2057 struct sock_fprog prog;
2058 pid_t tracer, mytid, mypid, parent;
2059 long syscall_nr;
2060 };
2061
tracer_ptrace(struct __test_metadata * _metadata,pid_t tracee,int status,void * args)2062 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
2063 int status, void *args)
2064 {
2065 int ret;
2066 unsigned long msg;
2067 static bool entry;
2068 long syscall_nr_val, syscall_ret_val;
2069 long *syscall_nr = NULL, *syscall_ret = NULL;
2070 FIXTURE_DATA(TRACE_syscall) *self = args;
2071
2072 EXPECT_EQ(WSTOPSIG(status) & 0x80, 0x80) {
2073 TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
2074 return;
2075 }
2076
2077 /*
2078 * The traditional way to tell PTRACE_SYSCALL entry/exit
2079 * is by counting.
2080 */
2081 entry = !entry;
2082
2083 /* Make sure we got an appropriate message. */
2084 ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
2085 EXPECT_EQ(0, ret);
2086 EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
2087 : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
2088
2089 /*
2090 * Some architectures only support setting return values during
2091 * syscall exit under ptrace, and on exit the syscall number may
2092 * no longer be available. Therefore, save the initial sycall
2093 * number here, so it can be examined during both entry and exit
2094 * phases.
2095 */
2096 if (entry)
2097 self->syscall_nr = get_syscall(_metadata, tracee);
2098
2099 /*
2100 * Depending on the architecture's syscall setting abilities, we
2101 * pick which things to set during this phase (entry or exit).
2102 */
2103 if (entry == ptrace_entry_set_syscall_nr)
2104 syscall_nr = &syscall_nr_val;
2105 if (entry == ptrace_entry_set_syscall_ret)
2106 syscall_ret = &syscall_ret_val;
2107
2108 /* Now handle the actual rewriting cases. */
2109 switch (self->syscall_nr) {
2110 case __NR_getpid:
2111 syscall_nr_val = __NR_getppid;
2112 /* Never change syscall return for this case. */
2113 syscall_ret = NULL;
2114 break;
2115 case __NR_gettid:
2116 syscall_nr_val = -1;
2117 syscall_ret_val = 45000;
2118 break;
2119 case __NR_openat:
2120 syscall_nr_val = -1;
2121 syscall_ret_val = -ESRCH;
2122 break;
2123 default:
2124 /* Unhandled, do nothing. */
2125 return;
2126 }
2127
2128 __change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
2129 }
2130
FIXTURE_VARIANT(TRACE_syscall)2131 FIXTURE_VARIANT(TRACE_syscall) {
2132 /*
2133 * All of the SECCOMP_RET_TRACE behaviors can be tested with either
2134 * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL.
2135 * This indicates if we should use SECCOMP_RET_TRACE (false), or
2136 * ptrace (true).
2137 */
2138 bool use_ptrace;
2139 };
2140
FIXTURE_VARIANT_ADD(TRACE_syscall,ptrace)2141 FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) {
2142 .use_ptrace = true,
2143 };
2144
FIXTURE_VARIANT_ADD(TRACE_syscall,seccomp)2145 FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) {
2146 .use_ptrace = false,
2147 };
2148
FIXTURE_SETUP(TRACE_syscall)2149 FIXTURE_SETUP(TRACE_syscall)
2150 {
2151 struct sock_filter filter[] = {
2152 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2153 offsetof(struct seccomp_data, nr)),
2154 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
2155 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
2156 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
2157 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
2158 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
2159 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
2160 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2161 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
2162 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2163 };
2164 struct sock_fprog prog = {
2165 .len = (unsigned short)ARRAY_SIZE(filter),
2166 .filter = filter,
2167 };
2168 long ret;
2169
2170 /* Prepare some testable syscall results. */
2171 self->mytid = syscall(__NR_gettid);
2172 ASSERT_GT(self->mytid, 0);
2173 ASSERT_NE(self->mytid, 1) {
2174 TH_LOG("Running this test as init is not supported. :)");
2175 }
2176
2177 self->mypid = getpid();
2178 ASSERT_GT(self->mypid, 0);
2179 ASSERT_EQ(self->mytid, self->mypid);
2180
2181 self->parent = getppid();
2182 ASSERT_GT(self->parent, 0);
2183 ASSERT_NE(self->parent, self->mypid);
2184
2185 /* Launch tracer. */
2186 self->tracer = setup_trace_fixture(_metadata,
2187 variant->use_ptrace ? tracer_ptrace
2188 : tracer_seccomp,
2189 self, variant->use_ptrace);
2190
2191 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2192 ASSERT_EQ(0, ret);
2193
2194 /* Do not install seccomp rewrite filters, as we'll use ptrace instead. */
2195 if (variant->use_ptrace)
2196 return;
2197
2198 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2199 ASSERT_EQ(0, ret);
2200 }
2201
FIXTURE_TEARDOWN(TRACE_syscall)2202 FIXTURE_TEARDOWN(TRACE_syscall)
2203 {
2204 teardown_trace_fixture(_metadata, self->tracer);
2205 }
2206
TEST(negative_ENOSYS)2207 TEST(negative_ENOSYS)
2208 {
2209 #if defined(__arm__)
2210 SKIP(return, "arm32 does not support calling syscall -1");
2211 #endif
2212 /*
2213 * There should be no difference between an "internal" skip
2214 * and userspace asking for syscall "-1".
2215 */
2216 errno = 0;
2217 EXPECT_EQ(-1, syscall(-1));
2218 EXPECT_EQ(errno, ENOSYS);
2219 /* And no difference for "still not valid but not -1". */
2220 errno = 0;
2221 EXPECT_EQ(-1, syscall(-101));
2222 EXPECT_EQ(errno, ENOSYS);
2223 }
2224
TEST_F(TRACE_syscall,negative_ENOSYS)2225 TEST_F(TRACE_syscall, negative_ENOSYS)
2226 {
2227 negative_ENOSYS(_metadata);
2228 }
2229
TEST_F(TRACE_syscall,syscall_allowed)2230 TEST_F(TRACE_syscall, syscall_allowed)
2231 {
2232 /* getppid works as expected (no changes). */
2233 EXPECT_EQ(self->parent, syscall(__NR_getppid));
2234 EXPECT_NE(self->mypid, syscall(__NR_getppid));
2235 }
2236
TEST_F(TRACE_syscall,syscall_redirected)2237 TEST_F(TRACE_syscall, syscall_redirected)
2238 {
2239 /* getpid has been redirected to getppid as expected. */
2240 EXPECT_EQ(self->parent, syscall(__NR_getpid));
2241 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2242 }
2243
TEST_F(TRACE_syscall,syscall_errno)2244 TEST_F(TRACE_syscall, syscall_errno)
2245 {
2246 /* Tracer should skip the open syscall, resulting in ESRCH. */
2247 EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
2248 }
2249
TEST_F(TRACE_syscall,syscall_faked)2250 TEST_F(TRACE_syscall, syscall_faked)
2251 {
2252 /* Tracer skips the gettid syscall and store altered return value. */
2253 EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
2254 }
2255
TEST_F_SIGNAL(TRACE_syscall,kill_immediate,SIGSYS)2256 TEST_F_SIGNAL(TRACE_syscall, kill_immediate, SIGSYS)
2257 {
2258 struct sock_filter filter[] = {
2259 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2260 offsetof(struct seccomp_data, nr)),
2261 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_mknodat, 0, 1),
2262 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
2263 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2264 };
2265 struct sock_fprog prog = {
2266 .len = (unsigned short)ARRAY_SIZE(filter),
2267 .filter = filter,
2268 };
2269 long ret;
2270
2271 /* Install "kill on mknodat" filter. */
2272 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2273 ASSERT_EQ(0, ret);
2274
2275 /* This should immediately die with SIGSYS, regardless of tracer. */
2276 EXPECT_EQ(-1, syscall(__NR_mknodat, -1, NULL, 0, 0));
2277 }
2278
TEST_F(TRACE_syscall,skip_after)2279 TEST_F(TRACE_syscall, skip_after)
2280 {
2281 struct sock_filter filter[] = {
2282 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2283 offsetof(struct seccomp_data, nr)),
2284 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2285 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
2286 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2287 };
2288 struct sock_fprog prog = {
2289 .len = (unsigned short)ARRAY_SIZE(filter),
2290 .filter = filter,
2291 };
2292 long ret;
2293
2294 /* Install additional "errno on getppid" filter. */
2295 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2296 ASSERT_EQ(0, ret);
2297
2298 /* Tracer will redirect getpid to getppid, and we should see EPERM. */
2299 errno = 0;
2300 EXPECT_EQ(-1, syscall(__NR_getpid));
2301 EXPECT_EQ(EPERM, errno);
2302 }
2303
TEST_F_SIGNAL(TRACE_syscall,kill_after,SIGSYS)2304 TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS)
2305 {
2306 struct sock_filter filter[] = {
2307 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2308 offsetof(struct seccomp_data, nr)),
2309 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
2310 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2311 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2312 };
2313 struct sock_fprog prog = {
2314 .len = (unsigned short)ARRAY_SIZE(filter),
2315 .filter = filter,
2316 };
2317 long ret;
2318
2319 /* Install additional "death on getppid" filter. */
2320 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
2321 ASSERT_EQ(0, ret);
2322
2323 /* Tracer will redirect getpid to getppid, and we should die. */
2324 EXPECT_NE(self->mypid, syscall(__NR_getpid));
2325 }
2326
TEST(seccomp_syscall)2327 TEST(seccomp_syscall)
2328 {
2329 struct sock_filter filter[] = {
2330 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2331 };
2332 struct sock_fprog prog = {
2333 .len = (unsigned short)ARRAY_SIZE(filter),
2334 .filter = filter,
2335 };
2336 long ret;
2337
2338 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
2339 ASSERT_EQ(0, ret) {
2340 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2341 }
2342
2343 /* Reject insane operation. */
2344 ret = seccomp(-1, 0, &prog);
2345 ASSERT_NE(ENOSYS, errno) {
2346 TH_LOG("Kernel does not support seccomp syscall!");
2347 }
2348 EXPECT_EQ(EINVAL, errno) {
2349 TH_LOG("Did not reject crazy op value!");
2350 }
2351
2352 /* Reject strict with flags or pointer. */
2353 ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
2354 EXPECT_EQ(EINVAL, errno) {
2355 TH_LOG("Did not reject mode strict with flags!");
2356 }
2357 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
2358 EXPECT_EQ(EINVAL, errno) {
2359 TH_LOG("Did not reject mode strict with uargs!");
2360 }
2361
2362 /* Reject insane args for filter. */
2363 ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
2364 EXPECT_EQ(EINVAL, errno) {
2365 TH_LOG("Did not reject crazy filter flags!");
2366 }
2367 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
2368 EXPECT_EQ(EFAULT, errno) {
2369 TH_LOG("Did not reject NULL filter!");
2370 }
2371
2372 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2373 EXPECT_EQ(0, errno) {
2374 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
2375 strerror(errno));
2376 }
2377 }
2378
TEST(seccomp_syscall_mode_lock)2379 TEST(seccomp_syscall_mode_lock)
2380 {
2381 struct sock_filter filter[] = {
2382 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2383 };
2384 struct sock_fprog prog = {
2385 .len = (unsigned short)ARRAY_SIZE(filter),
2386 .filter = filter,
2387 };
2388 long ret;
2389
2390 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2391 ASSERT_EQ(0, ret) {
2392 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2393 }
2394
2395 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2396 ASSERT_NE(ENOSYS, errno) {
2397 TH_LOG("Kernel does not support seccomp syscall!");
2398 }
2399 EXPECT_EQ(0, ret) {
2400 TH_LOG("Could not install filter!");
2401 }
2402
2403 /* Make sure neither entry point will switch to strict. */
2404 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
2405 EXPECT_EQ(EINVAL, errno) {
2406 TH_LOG("Switched to mode strict!");
2407 }
2408
2409 ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
2410 EXPECT_EQ(EINVAL, errno) {
2411 TH_LOG("Switched to mode strict!");
2412 }
2413 }
2414
2415 /*
2416 * Test detection of known and unknown filter flags. Userspace needs to be able
2417 * to check if a filter flag is supported by the current kernel and a good way
2418 * of doing that is by attempting to enter filter mode, with the flag bit in
2419 * question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
2420 * that the flag is valid and EINVAL indicates that the flag is invalid.
2421 */
TEST(detect_seccomp_filter_flags)2422 TEST(detect_seccomp_filter_flags)
2423 {
2424 unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
2425 SECCOMP_FILTER_FLAG_LOG,
2426 SECCOMP_FILTER_FLAG_SPEC_ALLOW,
2427 SECCOMP_FILTER_FLAG_NEW_LISTENER,
2428 SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
2429 unsigned int exclusive[] = {
2430 SECCOMP_FILTER_FLAG_TSYNC,
2431 SECCOMP_FILTER_FLAG_NEW_LISTENER };
2432 unsigned int flag, all_flags, exclusive_mask;
2433 int i;
2434 long ret;
2435
2436 /* Test detection of individual known-good filter flags */
2437 for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
2438 int bits = 0;
2439
2440 flag = flags[i];
2441 /* Make sure the flag is a single bit! */
2442 while (flag) {
2443 if (flag & 0x1)
2444 bits ++;
2445 flag >>= 1;
2446 }
2447 ASSERT_EQ(1, bits);
2448 flag = flags[i];
2449
2450 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2451 ASSERT_NE(ENOSYS, errno) {
2452 TH_LOG("Kernel does not support seccomp syscall!");
2453 }
2454 EXPECT_EQ(-1, ret);
2455 EXPECT_EQ(EFAULT, errno) {
2456 TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
2457 flag);
2458 }
2459
2460 all_flags |= flag;
2461 }
2462
2463 /*
2464 * Test detection of all known-good filter flags combined. But
2465 * for the exclusive flags we need to mask them out and try them
2466 * individually for the "all flags" testing.
2467 */
2468 exclusive_mask = 0;
2469 for (i = 0; i < ARRAY_SIZE(exclusive); i++)
2470 exclusive_mask |= exclusive[i];
2471 for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
2472 flag = all_flags & ~exclusive_mask;
2473 flag |= exclusive[i];
2474
2475 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2476 EXPECT_EQ(-1, ret);
2477 EXPECT_EQ(EFAULT, errno) {
2478 TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
2479 flag);
2480 }
2481 }
2482
2483 /* Test detection of an unknown filter flags, without exclusives. */
2484 flag = -1;
2485 flag &= ~exclusive_mask;
2486 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2487 EXPECT_EQ(-1, ret);
2488 EXPECT_EQ(EINVAL, errno) {
2489 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
2490 flag);
2491 }
2492
2493 /*
2494 * Test detection of an unknown filter flag that may simply need to be
2495 * added to this test
2496 */
2497 flag = flags[ARRAY_SIZE(flags) - 1] << 1;
2498 ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
2499 EXPECT_EQ(-1, ret);
2500 EXPECT_EQ(EINVAL, errno) {
2501 TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
2502 flag);
2503 }
2504 }
2505
TEST(TSYNC_first)2506 TEST(TSYNC_first)
2507 {
2508 struct sock_filter filter[] = {
2509 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2510 };
2511 struct sock_fprog prog = {
2512 .len = (unsigned short)ARRAY_SIZE(filter),
2513 .filter = filter,
2514 };
2515 long ret;
2516
2517 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
2518 ASSERT_EQ(0, ret) {
2519 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2520 }
2521
2522 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2523 &prog);
2524 ASSERT_NE(ENOSYS, errno) {
2525 TH_LOG("Kernel does not support seccomp syscall!");
2526 }
2527 EXPECT_EQ(0, ret) {
2528 TH_LOG("Could not install initial filter with TSYNC!");
2529 }
2530 }
2531
2532 #define TSYNC_SIBLINGS 2
2533 struct tsync_sibling {
2534 pthread_t tid;
2535 pid_t system_tid;
2536 sem_t *started;
2537 pthread_cond_t *cond;
2538 pthread_mutex_t *mutex;
2539 int diverge;
2540 int num_waits;
2541 struct sock_fprog *prog;
2542 struct __test_metadata *metadata;
2543 };
2544
2545 /*
2546 * To avoid joining joined threads (which is not allowed by Bionic),
2547 * make sure we both successfully join and clear the tid to skip a
2548 * later join attempt during fixture teardown. Any remaining threads
2549 * will be directly killed during teardown.
2550 */
2551 #define PTHREAD_JOIN(tid, status) \
2552 do { \
2553 int _rc = pthread_join(tid, status); \
2554 if (_rc) { \
2555 TH_LOG("pthread_join of tid %u failed: %d\n", \
2556 (unsigned int)tid, _rc); \
2557 } else { \
2558 tid = 0; \
2559 } \
2560 } while (0)
2561
FIXTURE(TSYNC)2562 FIXTURE(TSYNC) {
2563 struct sock_fprog root_prog, apply_prog;
2564 struct tsync_sibling sibling[TSYNC_SIBLINGS];
2565 sem_t started;
2566 pthread_cond_t cond;
2567 pthread_mutex_t mutex;
2568 int sibling_count;
2569 };
2570
FIXTURE_SETUP(TSYNC)2571 FIXTURE_SETUP(TSYNC)
2572 {
2573 struct sock_filter root_filter[] = {
2574 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2575 };
2576 struct sock_filter apply_filter[] = {
2577 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2578 offsetof(struct seccomp_data, nr)),
2579 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
2580 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
2581 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2582 };
2583
2584 memset(&self->root_prog, 0, sizeof(self->root_prog));
2585 memset(&self->apply_prog, 0, sizeof(self->apply_prog));
2586 memset(&self->sibling, 0, sizeof(self->sibling));
2587 self->root_prog.filter = malloc(sizeof(root_filter));
2588 ASSERT_NE(NULL, self->root_prog.filter);
2589 memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
2590 self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
2591
2592 self->apply_prog.filter = malloc(sizeof(apply_filter));
2593 ASSERT_NE(NULL, self->apply_prog.filter);
2594 memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
2595 self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
2596
2597 self->sibling_count = 0;
2598 pthread_mutex_init(&self->mutex, NULL);
2599 pthread_cond_init(&self->cond, NULL);
2600 sem_init(&self->started, 0, 0);
2601 self->sibling[0].tid = 0;
2602 self->sibling[0].cond = &self->cond;
2603 self->sibling[0].started = &self->started;
2604 self->sibling[0].mutex = &self->mutex;
2605 self->sibling[0].diverge = 0;
2606 self->sibling[0].num_waits = 1;
2607 self->sibling[0].prog = &self->root_prog;
2608 self->sibling[0].metadata = _metadata;
2609 self->sibling[1].tid = 0;
2610 self->sibling[1].cond = &self->cond;
2611 self->sibling[1].started = &self->started;
2612 self->sibling[1].mutex = &self->mutex;
2613 self->sibling[1].diverge = 0;
2614 self->sibling[1].prog = &self->root_prog;
2615 self->sibling[1].num_waits = 1;
2616 self->sibling[1].metadata = _metadata;
2617 }
2618
FIXTURE_TEARDOWN(TSYNC)2619 FIXTURE_TEARDOWN(TSYNC)
2620 {
2621 int sib = 0;
2622
2623 if (self->root_prog.filter)
2624 free(self->root_prog.filter);
2625 if (self->apply_prog.filter)
2626 free(self->apply_prog.filter);
2627
2628 for ( ; sib < self->sibling_count; ++sib) {
2629 struct tsync_sibling *s = &self->sibling[sib];
2630
2631 if (!s->tid)
2632 continue;
2633 /*
2634 * If a thread is still running, it may be stuck, so hit
2635 * it over the head really hard.
2636 */
2637 pthread_kill(s->tid, 9);
2638 }
2639 pthread_mutex_destroy(&self->mutex);
2640 pthread_cond_destroy(&self->cond);
2641 sem_destroy(&self->started);
2642 }
2643
tsync_sibling(void * data)2644 void *tsync_sibling(void *data)
2645 {
2646 long ret = 0;
2647 struct tsync_sibling *me = data;
2648
2649 me->system_tid = syscall(__NR_gettid);
2650
2651 pthread_mutex_lock(me->mutex);
2652 if (me->diverge) {
2653 /* Just re-apply the root prog to fork the tree */
2654 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
2655 me->prog, 0, 0);
2656 }
2657 sem_post(me->started);
2658 /* Return outside of started so parent notices failures. */
2659 if (ret) {
2660 pthread_mutex_unlock(me->mutex);
2661 return (void *)SIBLING_EXIT_FAILURE;
2662 }
2663 do {
2664 pthread_cond_wait(me->cond, me->mutex);
2665 me->num_waits = me->num_waits - 1;
2666 } while (me->num_waits);
2667 pthread_mutex_unlock(me->mutex);
2668
2669 ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
2670 if (!ret)
2671 return (void *)SIBLING_EXIT_NEWPRIVS;
2672 read(-1, NULL, 0);
2673 return (void *)SIBLING_EXIT_UNKILLED;
2674 }
2675
tsync_start_sibling(struct tsync_sibling * sibling)2676 void tsync_start_sibling(struct tsync_sibling *sibling)
2677 {
2678 pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
2679 }
2680
TEST_F(TSYNC,siblings_fail_prctl)2681 TEST_F(TSYNC, siblings_fail_prctl)
2682 {
2683 long ret;
2684 void *status;
2685 struct sock_filter filter[] = {
2686 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
2687 offsetof(struct seccomp_data, nr)),
2688 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
2689 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
2690 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
2691 };
2692 struct sock_fprog prog = {
2693 .len = (unsigned short)ARRAY_SIZE(filter),
2694 .filter = filter,
2695 };
2696
2697 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2698 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2699 }
2700
2701 /* Check prctl failure detection by requesting sib 0 diverge. */
2702 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
2703 ASSERT_NE(ENOSYS, errno) {
2704 TH_LOG("Kernel does not support seccomp syscall!");
2705 }
2706 ASSERT_EQ(0, ret) {
2707 TH_LOG("setting filter failed");
2708 }
2709
2710 self->sibling[0].diverge = 1;
2711 tsync_start_sibling(&self->sibling[0]);
2712 tsync_start_sibling(&self->sibling[1]);
2713
2714 while (self->sibling_count < TSYNC_SIBLINGS) {
2715 sem_wait(&self->started);
2716 self->sibling_count++;
2717 }
2718
2719 /* Signal the threads to clean up*/
2720 pthread_mutex_lock(&self->mutex);
2721 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2722 TH_LOG("cond broadcast non-zero");
2723 }
2724 pthread_mutex_unlock(&self->mutex);
2725
2726 /* Ensure diverging sibling failed to call prctl. */
2727 PTHREAD_JOIN(self->sibling[0].tid, &status);
2728 EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
2729 PTHREAD_JOIN(self->sibling[1].tid, &status);
2730 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2731 }
2732
TEST_F(TSYNC,two_siblings_with_ancestor)2733 TEST_F(TSYNC, two_siblings_with_ancestor)
2734 {
2735 long ret;
2736 void *status;
2737
2738 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2739 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2740 }
2741
2742 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2743 ASSERT_NE(ENOSYS, errno) {
2744 TH_LOG("Kernel does not support seccomp syscall!");
2745 }
2746 ASSERT_EQ(0, ret) {
2747 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2748 }
2749 tsync_start_sibling(&self->sibling[0]);
2750 tsync_start_sibling(&self->sibling[1]);
2751
2752 while (self->sibling_count < TSYNC_SIBLINGS) {
2753 sem_wait(&self->started);
2754 self->sibling_count++;
2755 }
2756
2757 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2758 &self->apply_prog);
2759 ASSERT_EQ(0, ret) {
2760 TH_LOG("Could install filter on all threads!");
2761 }
2762 /* Tell the siblings to test the policy */
2763 pthread_mutex_lock(&self->mutex);
2764 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2765 TH_LOG("cond broadcast non-zero");
2766 }
2767 pthread_mutex_unlock(&self->mutex);
2768 /* Ensure they are both killed and don't exit cleanly. */
2769 PTHREAD_JOIN(self->sibling[0].tid, &status);
2770 EXPECT_EQ(0x0, (long)status);
2771 PTHREAD_JOIN(self->sibling[1].tid, &status);
2772 EXPECT_EQ(0x0, (long)status);
2773 }
2774
TEST_F(TSYNC,two_sibling_want_nnp)2775 TEST_F(TSYNC, two_sibling_want_nnp)
2776 {
2777 void *status;
2778
2779 /* start siblings before any prctl() operations */
2780 tsync_start_sibling(&self->sibling[0]);
2781 tsync_start_sibling(&self->sibling[1]);
2782 while (self->sibling_count < TSYNC_SIBLINGS) {
2783 sem_wait(&self->started);
2784 self->sibling_count++;
2785 }
2786
2787 /* Tell the siblings to test no policy */
2788 pthread_mutex_lock(&self->mutex);
2789 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2790 TH_LOG("cond broadcast non-zero");
2791 }
2792 pthread_mutex_unlock(&self->mutex);
2793
2794 /* Ensure they are both upset about lacking nnp. */
2795 PTHREAD_JOIN(self->sibling[0].tid, &status);
2796 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2797 PTHREAD_JOIN(self->sibling[1].tid, &status);
2798 EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
2799 }
2800
TEST_F(TSYNC,two_siblings_with_no_filter)2801 TEST_F(TSYNC, two_siblings_with_no_filter)
2802 {
2803 long ret;
2804 void *status;
2805
2806 /* start siblings before any prctl() operations */
2807 tsync_start_sibling(&self->sibling[0]);
2808 tsync_start_sibling(&self->sibling[1]);
2809 while (self->sibling_count < TSYNC_SIBLINGS) {
2810 sem_wait(&self->started);
2811 self->sibling_count++;
2812 }
2813
2814 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2815 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2816 }
2817
2818 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2819 &self->apply_prog);
2820 ASSERT_NE(ENOSYS, errno) {
2821 TH_LOG("Kernel does not support seccomp syscall!");
2822 }
2823 ASSERT_EQ(0, ret) {
2824 TH_LOG("Could install filter on all threads!");
2825 }
2826
2827 /* Tell the siblings to test the policy */
2828 pthread_mutex_lock(&self->mutex);
2829 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2830 TH_LOG("cond broadcast non-zero");
2831 }
2832 pthread_mutex_unlock(&self->mutex);
2833
2834 /* Ensure they are both killed and don't exit cleanly. */
2835 PTHREAD_JOIN(self->sibling[0].tid, &status);
2836 EXPECT_EQ(0x0, (long)status);
2837 PTHREAD_JOIN(self->sibling[1].tid, &status);
2838 EXPECT_EQ(0x0, (long)status);
2839 }
2840
TEST_F(TSYNC,two_siblings_with_one_divergence)2841 TEST_F(TSYNC, two_siblings_with_one_divergence)
2842 {
2843 long ret;
2844 void *status;
2845
2846 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2847 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2848 }
2849
2850 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2851 ASSERT_NE(ENOSYS, errno) {
2852 TH_LOG("Kernel does not support seccomp syscall!");
2853 }
2854 ASSERT_EQ(0, ret) {
2855 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2856 }
2857 self->sibling[0].diverge = 1;
2858 tsync_start_sibling(&self->sibling[0]);
2859 tsync_start_sibling(&self->sibling[1]);
2860
2861 while (self->sibling_count < TSYNC_SIBLINGS) {
2862 sem_wait(&self->started);
2863 self->sibling_count++;
2864 }
2865
2866 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2867 &self->apply_prog);
2868 ASSERT_EQ(self->sibling[0].system_tid, ret) {
2869 TH_LOG("Did not fail on diverged sibling.");
2870 }
2871
2872 /* Wake the threads */
2873 pthread_mutex_lock(&self->mutex);
2874 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2875 TH_LOG("cond broadcast non-zero");
2876 }
2877 pthread_mutex_unlock(&self->mutex);
2878
2879 /* Ensure they are both unkilled. */
2880 PTHREAD_JOIN(self->sibling[0].tid, &status);
2881 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2882 PTHREAD_JOIN(self->sibling[1].tid, &status);
2883 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2884 }
2885
TEST_F(TSYNC,two_siblings_with_one_divergence_no_tid_in_err)2886 TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
2887 {
2888 long ret, flags;
2889 void *status;
2890
2891 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2892 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2893 }
2894
2895 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2896 ASSERT_NE(ENOSYS, errno) {
2897 TH_LOG("Kernel does not support seccomp syscall!");
2898 }
2899 ASSERT_EQ(0, ret) {
2900 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2901 }
2902 self->sibling[0].diverge = 1;
2903 tsync_start_sibling(&self->sibling[0]);
2904 tsync_start_sibling(&self->sibling[1]);
2905
2906 while (self->sibling_count < TSYNC_SIBLINGS) {
2907 sem_wait(&self->started);
2908 self->sibling_count++;
2909 }
2910
2911 flags = SECCOMP_FILTER_FLAG_TSYNC | \
2912 SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
2913 ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
2914 ASSERT_EQ(ESRCH, errno) {
2915 TH_LOG("Did not return ESRCH for diverged sibling.");
2916 }
2917 ASSERT_EQ(-1, ret) {
2918 TH_LOG("Did not fail on diverged sibling.");
2919 }
2920
2921 /* Wake the threads */
2922 pthread_mutex_lock(&self->mutex);
2923 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2924 TH_LOG("cond broadcast non-zero");
2925 }
2926 pthread_mutex_unlock(&self->mutex);
2927
2928 /* Ensure they are both unkilled. */
2929 PTHREAD_JOIN(self->sibling[0].tid, &status);
2930 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2931 PTHREAD_JOIN(self->sibling[1].tid, &status);
2932 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2933 }
2934
TEST_F(TSYNC,two_siblings_not_under_filter)2935 TEST_F(TSYNC, two_siblings_not_under_filter)
2936 {
2937 long ret, sib;
2938 void *status;
2939 struct timespec delay = { .tv_nsec = 100000000 };
2940
2941 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
2942 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
2943 }
2944
2945 /*
2946 * Sibling 0 will have its own seccomp policy
2947 * and Sibling 1 will not be under seccomp at
2948 * all. Sibling 1 will enter seccomp and 0
2949 * will cause failure.
2950 */
2951 self->sibling[0].diverge = 1;
2952 tsync_start_sibling(&self->sibling[0]);
2953 tsync_start_sibling(&self->sibling[1]);
2954
2955 while (self->sibling_count < TSYNC_SIBLINGS) {
2956 sem_wait(&self->started);
2957 self->sibling_count++;
2958 }
2959
2960 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
2961 ASSERT_NE(ENOSYS, errno) {
2962 TH_LOG("Kernel does not support seccomp syscall!");
2963 }
2964 ASSERT_EQ(0, ret) {
2965 TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
2966 }
2967
2968 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2969 &self->apply_prog);
2970 ASSERT_EQ(ret, self->sibling[0].system_tid) {
2971 TH_LOG("Did not fail on diverged sibling.");
2972 }
2973 sib = 1;
2974 if (ret == self->sibling[0].system_tid)
2975 sib = 0;
2976
2977 pthread_mutex_lock(&self->mutex);
2978
2979 /* Increment the other siblings num_waits so we can clean up
2980 * the one we just saw.
2981 */
2982 self->sibling[!sib].num_waits += 1;
2983
2984 /* Signal the thread to clean up*/
2985 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
2986 TH_LOG("cond broadcast non-zero");
2987 }
2988 pthread_mutex_unlock(&self->mutex);
2989 PTHREAD_JOIN(self->sibling[sib].tid, &status);
2990 EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
2991 /* Poll for actual task death. pthread_join doesn't guarantee it. */
2992 while (!kill(self->sibling[sib].system_tid, 0))
2993 nanosleep(&delay, NULL);
2994 /* Switch to the remaining sibling */
2995 sib = !sib;
2996
2997 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
2998 &self->apply_prog);
2999 ASSERT_EQ(0, ret) {
3000 TH_LOG("Expected the remaining sibling to sync");
3001 };
3002
3003 pthread_mutex_lock(&self->mutex);
3004
3005 /* If remaining sibling didn't have a chance to wake up during
3006 * the first broadcast, manually reduce the num_waits now.
3007 */
3008 if (self->sibling[sib].num_waits > 1)
3009 self->sibling[sib].num_waits = 1;
3010 ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
3011 TH_LOG("cond broadcast non-zero");
3012 }
3013 pthread_mutex_unlock(&self->mutex);
3014 PTHREAD_JOIN(self->sibling[sib].tid, &status);
3015 EXPECT_EQ(0, (long)status);
3016 /* Poll for actual task death. pthread_join doesn't guarantee it. */
3017 while (!kill(self->sibling[sib].system_tid, 0))
3018 nanosleep(&delay, NULL);
3019
3020 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
3021 &self->apply_prog);
3022 ASSERT_EQ(0, ret); /* just us chickens */
3023 }
3024
3025 /* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)3026 TEST(syscall_restart)
3027 {
3028 long ret;
3029 unsigned long msg;
3030 pid_t child_pid;
3031 int pipefd[2];
3032 int status;
3033 siginfo_t info = { };
3034 struct sock_filter filter[] = {
3035 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3036 offsetof(struct seccomp_data, nr)),
3037
3038 #ifdef __NR_sigreturn
3039 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0),
3040 #endif
3041 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0),
3042 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0),
3043 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0),
3044 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0),
3045 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0),
3046 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
3047
3048 /* Allow __NR_write for easy logging. */
3049 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
3050 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3051 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
3052 /* The nanosleep jump target. */
3053 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
3054 /* The restart_syscall jump target. */
3055 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
3056 };
3057 struct sock_fprog prog = {
3058 .len = (unsigned short)ARRAY_SIZE(filter),
3059 .filter = filter,
3060 };
3061 #if defined(__arm__)
3062 struct utsname utsbuf;
3063 #endif
3064
3065 ASSERT_EQ(0, pipe(pipefd));
3066
3067 child_pid = fork();
3068 ASSERT_LE(0, child_pid);
3069 if (child_pid == 0) {
3070 /* Child uses EXPECT not ASSERT to deliver status correctly. */
3071 char buf = ' ';
3072 struct timespec timeout = { };
3073
3074 /* Attach parent as tracer and stop. */
3075 EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
3076 EXPECT_EQ(0, raise(SIGSTOP));
3077
3078 EXPECT_EQ(0, close(pipefd[1]));
3079
3080 EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
3081 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3082 }
3083
3084 ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
3085 EXPECT_EQ(0, ret) {
3086 TH_LOG("Failed to install filter!");
3087 }
3088
3089 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3090 TH_LOG("Failed to read() sync from parent");
3091 }
3092 EXPECT_EQ('.', buf) {
3093 TH_LOG("Failed to get sync data from read()");
3094 }
3095
3096 /* Start nanosleep to be interrupted. */
3097 timeout.tv_sec = 1;
3098 errno = 0;
3099 EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
3100 TH_LOG("Call to nanosleep() failed (errno %d: %s)",
3101 errno, strerror(errno));
3102 }
3103
3104 /* Read final sync from parent. */
3105 EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
3106 TH_LOG("Failed final read() from parent");
3107 }
3108 EXPECT_EQ('!', buf) {
3109 TH_LOG("Failed to get final data from read()");
3110 }
3111
3112 /* Directly report the status of our test harness results. */
3113 syscall(__NR_exit, _metadata->exit_code);
3114 }
3115 EXPECT_EQ(0, close(pipefd[0]));
3116
3117 /* Attach to child, setup options, and release. */
3118 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3119 ASSERT_EQ(true, WIFSTOPPED(status));
3120 ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
3121 PTRACE_O_TRACESECCOMP));
3122 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3123 ASSERT_EQ(1, write(pipefd[1], ".", 1));
3124
3125 /* Wait for nanosleep() to start. */
3126 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3127 ASSERT_EQ(true, WIFSTOPPED(status));
3128 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3129 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3130 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3131 ASSERT_EQ(0x100, msg);
3132 ret = get_syscall(_metadata, child_pid);
3133 EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep);
3134
3135 /* Might as well check siginfo for sanity while we're here. */
3136 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3137 ASSERT_EQ(SIGTRAP, info.si_signo);
3138 ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
3139 EXPECT_EQ(0, info.si_errno);
3140 EXPECT_EQ(getuid(), info.si_uid);
3141 /* Verify signal delivery came from child (seccomp-triggered). */
3142 EXPECT_EQ(child_pid, info.si_pid);
3143
3144 /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
3145 ASSERT_EQ(0, kill(child_pid, SIGSTOP));
3146 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3147 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3148 ASSERT_EQ(true, WIFSTOPPED(status));
3149 ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
3150 ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
3151 /*
3152 * There is no siginfo on SIGSTOP any more, so we can't verify
3153 * signal delivery came from parent now (getpid() == info.si_pid).
3154 * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
3155 * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
3156 */
3157 EXPECT_EQ(SIGSTOP, info.si_signo);
3158
3159 /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
3160 ASSERT_EQ(0, kill(child_pid, SIGCONT));
3161 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3162 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3163 ASSERT_EQ(true, WIFSTOPPED(status));
3164 ASSERT_EQ(SIGCONT, WSTOPSIG(status));
3165 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3166
3167 /* Wait for restart_syscall() to start. */
3168 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3169 ASSERT_EQ(true, WIFSTOPPED(status));
3170 ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
3171 ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
3172 ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
3173
3174 ASSERT_EQ(0x200, msg);
3175 ret = get_syscall(_metadata, child_pid);
3176 #if defined(__arm__)
3177 /*
3178 * - native ARM registers do NOT expose true syscall.
3179 * - compat ARM registers on ARM64 DO expose true syscall.
3180 * - values of utsbuf.machine include 'armv8l' or 'armb8b'
3181 * for ARM64 running in compat mode.
3182 */
3183 ASSERT_EQ(0, uname(&utsbuf));
3184 if ((strncmp(utsbuf.machine, "arm", 3) == 0) &&
3185 (strncmp(utsbuf.machine, "armv8l", 6) != 0) &&
3186 (strncmp(utsbuf.machine, "armv8b", 6) != 0)) {
3187 EXPECT_EQ(__NR_nanosleep, ret);
3188 } else
3189 #endif
3190 {
3191 EXPECT_EQ(__NR_restart_syscall, ret);
3192 }
3193
3194 /* Write again to end test. */
3195 ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
3196 ASSERT_EQ(1, write(pipefd[1], "!", 1));
3197 EXPECT_EQ(0, close(pipefd[1]));
3198
3199 ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
3200 if (WIFSIGNALED(status) || WEXITSTATUS(status))
3201 _metadata->exit_code = KSFT_FAIL;
3202 }
3203
TEST_SIGNAL(filter_flag_log,SIGSYS)3204 TEST_SIGNAL(filter_flag_log, SIGSYS)
3205 {
3206 struct sock_filter allow_filter[] = {
3207 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3208 };
3209 struct sock_filter kill_filter[] = {
3210 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3211 offsetof(struct seccomp_data, nr)),
3212 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
3213 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
3214 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3215 };
3216 struct sock_fprog allow_prog = {
3217 .len = (unsigned short)ARRAY_SIZE(allow_filter),
3218 .filter = allow_filter,
3219 };
3220 struct sock_fprog kill_prog = {
3221 .len = (unsigned short)ARRAY_SIZE(kill_filter),
3222 .filter = kill_filter,
3223 };
3224 long ret;
3225 pid_t parent = getppid();
3226
3227 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3228 ASSERT_EQ(0, ret);
3229
3230 /* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
3231 ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
3232 &allow_prog);
3233 ASSERT_NE(ENOSYS, errno) {
3234 TH_LOG("Kernel does not support seccomp syscall!");
3235 }
3236 EXPECT_NE(0, ret) {
3237 TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
3238 }
3239 EXPECT_EQ(EINVAL, errno) {
3240 TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
3241 }
3242
3243 /* Verify that a simple, permissive filter can be added with no flags */
3244 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
3245 EXPECT_EQ(0, ret);
3246
3247 /* See if the same filter can be added with the FILTER_FLAG_LOG flag */
3248 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3249 &allow_prog);
3250 ASSERT_NE(EINVAL, errno) {
3251 TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
3252 }
3253 EXPECT_EQ(0, ret);
3254
3255 /* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
3256 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
3257 &kill_prog);
3258 EXPECT_EQ(0, ret);
3259
3260 EXPECT_EQ(parent, syscall(__NR_getppid));
3261 /* getpid() should never return. */
3262 EXPECT_EQ(0, syscall(__NR_getpid));
3263 }
3264
TEST(get_action_avail)3265 TEST(get_action_avail)
3266 {
3267 __u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
3268 SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
3269 SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
3270 __u32 unknown_action = 0x10000000U;
3271 int i;
3272 long ret;
3273
3274 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
3275 ASSERT_NE(ENOSYS, errno) {
3276 TH_LOG("Kernel does not support seccomp syscall!");
3277 }
3278 ASSERT_NE(EINVAL, errno) {
3279 TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
3280 }
3281 EXPECT_EQ(ret, 0);
3282
3283 for (i = 0; i < ARRAY_SIZE(actions); i++) {
3284 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
3285 EXPECT_EQ(ret, 0) {
3286 TH_LOG("Expected action (0x%X) not available!",
3287 actions[i]);
3288 }
3289 }
3290
3291 /* Check that an unknown action is handled properly (EOPNOTSUPP) */
3292 ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
3293 EXPECT_EQ(ret, -1);
3294 EXPECT_EQ(errno, EOPNOTSUPP);
3295 }
3296
TEST(get_metadata)3297 TEST(get_metadata)
3298 {
3299 pid_t pid;
3300 int pipefd[2];
3301 char buf;
3302 struct seccomp_metadata md;
3303 long ret;
3304
3305 /* Only real root can get metadata. */
3306 if (geteuid()) {
3307 SKIP(return, "get_metadata requires real root");
3308 return;
3309 }
3310
3311 ASSERT_EQ(0, pipe(pipefd));
3312
3313 pid = fork();
3314 ASSERT_GE(pid, 0);
3315 if (pid == 0) {
3316 struct sock_filter filter[] = {
3317 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3318 };
3319 struct sock_fprog prog = {
3320 .len = (unsigned short)ARRAY_SIZE(filter),
3321 .filter = filter,
3322 };
3323
3324 /* one with log, one without */
3325 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
3326 SECCOMP_FILTER_FLAG_LOG, &prog));
3327 EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
3328
3329 EXPECT_EQ(0, close(pipefd[0]));
3330 ASSERT_EQ(1, write(pipefd[1], "1", 1));
3331 ASSERT_EQ(0, close(pipefd[1]));
3332
3333 while (1)
3334 sleep(100);
3335 }
3336
3337 ASSERT_EQ(0, close(pipefd[1]));
3338 ASSERT_EQ(1, read(pipefd[0], &buf, 1));
3339
3340 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
3341 ASSERT_EQ(pid, waitpid(pid, NULL, 0));
3342
3343 /* Past here must not use ASSERT or child process is never killed. */
3344
3345 md.filter_off = 0;
3346 errno = 0;
3347 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3348 EXPECT_EQ(sizeof(md), ret) {
3349 if (errno == EINVAL)
3350 SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
3351 }
3352
3353 EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
3354 EXPECT_EQ(md.filter_off, 0);
3355
3356 md.filter_off = 1;
3357 ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
3358 EXPECT_EQ(sizeof(md), ret);
3359 EXPECT_EQ(md.flags, 0);
3360 EXPECT_EQ(md.filter_off, 1);
3361
3362 skip:
3363 ASSERT_EQ(0, kill(pid, SIGKILL));
3364 }
3365
user_notif_syscall(int nr,unsigned int flags)3366 static int user_notif_syscall(int nr, unsigned int flags)
3367 {
3368 struct sock_filter filter[] = {
3369 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
3370 offsetof(struct seccomp_data, nr)),
3371 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
3372 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
3373 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3374 };
3375
3376 struct sock_fprog prog = {
3377 .len = (unsigned short)ARRAY_SIZE(filter),
3378 .filter = filter,
3379 };
3380
3381 return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
3382 }
3383
3384 #define USER_NOTIF_MAGIC INT_MAX
TEST(user_notification_basic)3385 TEST(user_notification_basic)
3386 {
3387 pid_t pid;
3388 long ret;
3389 int status, listener;
3390 struct seccomp_notif req = {};
3391 struct seccomp_notif_resp resp = {};
3392 struct pollfd pollfd;
3393
3394 struct sock_filter filter[] = {
3395 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
3396 };
3397 struct sock_fprog prog = {
3398 .len = (unsigned short)ARRAY_SIZE(filter),
3399 .filter = filter,
3400 };
3401
3402 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3403 ASSERT_EQ(0, ret) {
3404 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3405 }
3406
3407 pid = fork();
3408 ASSERT_GE(pid, 0);
3409
3410 /* Check that we get -ENOSYS with no listener attached */
3411 if (pid == 0) {
3412 if (user_notif_syscall(__NR_getppid, 0) < 0)
3413 exit(1);
3414 ret = syscall(__NR_getppid);
3415 exit(ret >= 0 || errno != ENOSYS);
3416 }
3417
3418 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3419 EXPECT_EQ(true, WIFEXITED(status));
3420 EXPECT_EQ(0, WEXITSTATUS(status));
3421
3422 /* Add some no-op filters for grins. */
3423 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3424 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3425 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3426 EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
3427
3428 /* Check that the basic notification machinery works */
3429 listener = user_notif_syscall(__NR_getppid,
3430 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3431 ASSERT_GE(listener, 0);
3432
3433 /* Installing a second listener in the chain should EBUSY */
3434 EXPECT_EQ(user_notif_syscall(__NR_getppid,
3435 SECCOMP_FILTER_FLAG_NEW_LISTENER),
3436 -1);
3437 EXPECT_EQ(errno, EBUSY);
3438
3439 pid = fork();
3440 ASSERT_GE(pid, 0);
3441
3442 if (pid == 0) {
3443 ret = syscall(__NR_getppid);
3444 exit(ret != USER_NOTIF_MAGIC);
3445 }
3446
3447 pollfd.fd = listener;
3448 pollfd.events = POLLIN | POLLOUT;
3449
3450 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3451 EXPECT_EQ(pollfd.revents, POLLIN);
3452
3453 /* Test that we can't pass garbage to the kernel. */
3454 memset(&req, 0, sizeof(req));
3455 req.pid = -1;
3456 errno = 0;
3457 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
3458 EXPECT_EQ(-1, ret);
3459 EXPECT_EQ(EINVAL, errno);
3460
3461 if (ret) {
3462 req.pid = 0;
3463 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3464 }
3465
3466 pollfd.fd = listener;
3467 pollfd.events = POLLIN | POLLOUT;
3468
3469 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3470 EXPECT_EQ(pollfd.revents, POLLOUT);
3471
3472 EXPECT_EQ(req.data.nr, __NR_getppid);
3473
3474 resp.id = req.id;
3475 resp.error = 0;
3476 resp.val = USER_NOTIF_MAGIC;
3477
3478 /* check that we make sure flags == 0 */
3479 resp.flags = 1;
3480 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3481 EXPECT_EQ(errno, EINVAL);
3482
3483 resp.flags = 0;
3484 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3485
3486 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3487 EXPECT_EQ(true, WIFEXITED(status));
3488 EXPECT_EQ(0, WEXITSTATUS(status));
3489 }
3490
TEST(user_notification_with_tsync)3491 TEST(user_notification_with_tsync)
3492 {
3493 int ret;
3494 unsigned int flags;
3495
3496 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3497 ASSERT_EQ(0, ret) {
3498 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3499 }
3500
3501 /* these were exclusive */
3502 flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
3503 SECCOMP_FILTER_FLAG_TSYNC;
3504 ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags));
3505 ASSERT_EQ(EINVAL, errno);
3506
3507 /* but now they're not */
3508 flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
3509 ret = user_notif_syscall(__NR_getppid, flags);
3510 close(ret);
3511 ASSERT_LE(0, ret);
3512 }
3513
TEST(user_notification_kill_in_middle)3514 TEST(user_notification_kill_in_middle)
3515 {
3516 pid_t pid;
3517 long ret;
3518 int listener;
3519 struct seccomp_notif req = {};
3520 struct seccomp_notif_resp resp = {};
3521
3522 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3523 ASSERT_EQ(0, ret) {
3524 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3525 }
3526
3527 listener = user_notif_syscall(__NR_getppid,
3528 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3529 ASSERT_GE(listener, 0);
3530
3531 /*
3532 * Check that nothing bad happens when we kill the task in the middle
3533 * of a syscall.
3534 */
3535 pid = fork();
3536 ASSERT_GE(pid, 0);
3537
3538 if (pid == 0) {
3539 ret = syscall(__NR_getppid);
3540 exit(ret != USER_NOTIF_MAGIC);
3541 }
3542
3543 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3544 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
3545
3546 EXPECT_EQ(kill(pid, SIGKILL), 0);
3547 EXPECT_EQ(waitpid(pid, NULL, 0), pid);
3548
3549 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
3550
3551 resp.id = req.id;
3552 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
3553 EXPECT_EQ(ret, -1);
3554 EXPECT_EQ(errno, ENOENT);
3555 }
3556
3557 static int handled = -1;
3558
signal_handler(int signal)3559 static void signal_handler(int signal)
3560 {
3561 if (write(handled, "c", 1) != 1)
3562 perror("write from signal");
3563 }
3564
signal_handler_nop(int signal)3565 static void signal_handler_nop(int signal)
3566 {
3567 }
3568
TEST(user_notification_signal)3569 TEST(user_notification_signal)
3570 {
3571 pid_t pid;
3572 long ret;
3573 int status, listener, sk_pair[2];
3574 struct seccomp_notif req = {};
3575 struct seccomp_notif_resp resp = {};
3576 char c;
3577
3578 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3579 ASSERT_EQ(0, ret) {
3580 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3581 }
3582
3583 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
3584
3585 listener = user_notif_syscall(__NR_gettid,
3586 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3587 ASSERT_GE(listener, 0);
3588
3589 pid = fork();
3590 ASSERT_GE(pid, 0);
3591
3592 if (pid == 0) {
3593 close(sk_pair[0]);
3594 handled = sk_pair[1];
3595 if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
3596 perror("signal");
3597 exit(1);
3598 }
3599 /*
3600 * ERESTARTSYS behavior is a bit hard to test, because we need
3601 * to rely on a signal that has not yet been handled. Let's at
3602 * least check that the error code gets propagated through, and
3603 * hope that it doesn't break when there is actually a signal :)
3604 */
3605 ret = syscall(__NR_gettid);
3606 exit(!(ret == -1 && errno == 512));
3607 }
3608
3609 close(sk_pair[1]);
3610
3611 memset(&req, 0, sizeof(req));
3612 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3613
3614 EXPECT_EQ(kill(pid, SIGUSR1), 0);
3615
3616 /*
3617 * Make sure the signal really is delivered, which means we're not
3618 * stuck in the user notification code any more and the notification
3619 * should be dead.
3620 */
3621 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
3622
3623 resp.id = req.id;
3624 resp.error = -EPERM;
3625 resp.val = 0;
3626
3627 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3628 EXPECT_EQ(errno, ENOENT);
3629
3630 memset(&req, 0, sizeof(req));
3631 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3632
3633 resp.id = req.id;
3634 resp.error = -512; /* -ERESTARTSYS */
3635 resp.val = 0;
3636
3637 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3638
3639 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3640 EXPECT_EQ(true, WIFEXITED(status));
3641 EXPECT_EQ(0, WEXITSTATUS(status));
3642 }
3643
TEST(user_notification_closed_listener)3644 TEST(user_notification_closed_listener)
3645 {
3646 pid_t pid;
3647 long ret;
3648 int status, listener;
3649
3650 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3651 ASSERT_EQ(0, ret) {
3652 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3653 }
3654
3655 listener = user_notif_syscall(__NR_getppid,
3656 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3657 ASSERT_GE(listener, 0);
3658
3659 /*
3660 * Check that we get an ENOSYS when the listener is closed.
3661 */
3662 pid = fork();
3663 ASSERT_GE(pid, 0);
3664 if (pid == 0) {
3665 close(listener);
3666 ret = syscall(__NR_getppid);
3667 exit(ret != -1 && errno != ENOSYS);
3668 }
3669
3670 close(listener);
3671
3672 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3673 EXPECT_EQ(true, WIFEXITED(status));
3674 EXPECT_EQ(0, WEXITSTATUS(status));
3675 }
3676
3677 /*
3678 * Check that a pid in a child namespace still shows up as valid in ours.
3679 */
TEST(user_notification_child_pid_ns)3680 TEST(user_notification_child_pid_ns)
3681 {
3682 pid_t pid;
3683 int status, listener;
3684 struct seccomp_notif req = {};
3685 struct seccomp_notif_resp resp = {};
3686
3687 ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
3688 if (errno == EINVAL)
3689 SKIP(return, "kernel missing CLONE_NEWUSER support");
3690 };
3691
3692 listener = user_notif_syscall(__NR_getppid,
3693 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3694 ASSERT_GE(listener, 0);
3695
3696 pid = fork();
3697 ASSERT_GE(pid, 0);
3698
3699 if (pid == 0)
3700 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3701
3702 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3703 EXPECT_EQ(req.pid, pid);
3704
3705 resp.id = req.id;
3706 resp.error = 0;
3707 resp.val = USER_NOTIF_MAGIC;
3708
3709 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3710
3711 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3712 EXPECT_EQ(true, WIFEXITED(status));
3713 EXPECT_EQ(0, WEXITSTATUS(status));
3714 close(listener);
3715 }
3716
3717 /*
3718 * Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
3719 * invalid.
3720 */
TEST(user_notification_sibling_pid_ns)3721 TEST(user_notification_sibling_pid_ns)
3722 {
3723 pid_t pid, pid2;
3724 int status, listener;
3725 struct seccomp_notif req = {};
3726 struct seccomp_notif_resp resp = {};
3727
3728 ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
3729 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3730 }
3731
3732 listener = user_notif_syscall(__NR_getppid,
3733 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3734 ASSERT_GE(listener, 0);
3735
3736 pid = fork();
3737 ASSERT_GE(pid, 0);
3738
3739 if (pid == 0) {
3740 ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
3741 if (errno == EPERM)
3742 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
3743 else if (errno == EINVAL)
3744 SKIP(return, "CLONE_NEWPID is invalid (missing CONFIG_PID_NS?)");
3745 }
3746
3747 pid2 = fork();
3748 ASSERT_GE(pid2, 0);
3749
3750 if (pid2 == 0)
3751 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3752
3753 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3754 EXPECT_EQ(true, WIFEXITED(status));
3755 EXPECT_EQ(0, WEXITSTATUS(status));
3756 exit(WEXITSTATUS(status));
3757 }
3758
3759 /* Create the sibling ns, and sibling in it. */
3760 ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
3761 if (errno == EPERM)
3762 SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
3763 else if (errno == EINVAL)
3764 SKIP(return, "CLONE_NEWPID is invalid (missing CONFIG_PID_NS?)");
3765 }
3766 ASSERT_EQ(errno, 0);
3767
3768 pid2 = fork();
3769 ASSERT_GE(pid2, 0);
3770
3771 if (pid2 == 0) {
3772 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3773 /*
3774 * The pid should be 0, i.e. the task is in some namespace that
3775 * we can't "see".
3776 */
3777 EXPECT_EQ(req.pid, 0);
3778
3779 resp.id = req.id;
3780 resp.error = 0;
3781 resp.val = USER_NOTIF_MAGIC;
3782
3783 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3784 exit(0);
3785 }
3786
3787 close(listener);
3788
3789 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3790 EXPECT_EQ(true, WIFEXITED(status));
3791 EXPECT_EQ(0, WEXITSTATUS(status));
3792
3793 EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
3794 EXPECT_EQ(true, WIFEXITED(status));
3795 EXPECT_EQ(0, WEXITSTATUS(status));
3796 }
3797
TEST(user_notification_fault_recv)3798 TEST(user_notification_fault_recv)
3799 {
3800 pid_t pid;
3801 int status, listener;
3802 struct seccomp_notif req = {};
3803 struct seccomp_notif_resp resp = {};
3804
3805 ASSERT_EQ(unshare(CLONE_NEWUSER), 0) {
3806 if (errno == EINVAL)
3807 SKIP(return, "kernel missing CLONE_NEWUSER support");
3808 }
3809
3810 listener = user_notif_syscall(__NR_getppid,
3811 SECCOMP_FILTER_FLAG_NEW_LISTENER);
3812 ASSERT_GE(listener, 0);
3813
3814 pid = fork();
3815 ASSERT_GE(pid, 0);
3816
3817 if (pid == 0)
3818 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
3819
3820 /* Do a bad recv() */
3821 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
3822 EXPECT_EQ(errno, EFAULT);
3823
3824 /* We should still be able to receive this notification, though. */
3825 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3826 EXPECT_EQ(req.pid, pid);
3827
3828 resp.id = req.id;
3829 resp.error = 0;
3830 resp.val = USER_NOTIF_MAGIC;
3831
3832 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
3833
3834 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3835 EXPECT_EQ(true, WIFEXITED(status));
3836 EXPECT_EQ(0, WEXITSTATUS(status));
3837 }
3838
TEST(seccomp_get_notif_sizes)3839 TEST(seccomp_get_notif_sizes)
3840 {
3841 struct seccomp_notif_sizes sizes;
3842
3843 ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
3844 EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
3845 EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
3846 }
3847
TEST(user_notification_continue)3848 TEST(user_notification_continue)
3849 {
3850 pid_t pid;
3851 long ret;
3852 int status, listener;
3853 struct seccomp_notif req = {};
3854 struct seccomp_notif_resp resp = {};
3855 struct pollfd pollfd;
3856
3857 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3858 ASSERT_EQ(0, ret) {
3859 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3860 }
3861
3862 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3863 ASSERT_GE(listener, 0);
3864
3865 pid = fork();
3866 ASSERT_GE(pid, 0);
3867
3868 if (pid == 0) {
3869 int dup_fd, pipe_fds[2];
3870 pid_t self;
3871
3872 ASSERT_GE(pipe(pipe_fds), 0);
3873
3874 dup_fd = dup(pipe_fds[0]);
3875 ASSERT_GE(dup_fd, 0);
3876 EXPECT_NE(pipe_fds[0], dup_fd);
3877
3878 self = getpid();
3879 ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
3880 exit(0);
3881 }
3882
3883 pollfd.fd = listener;
3884 pollfd.events = POLLIN | POLLOUT;
3885
3886 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3887 EXPECT_EQ(pollfd.revents, POLLIN);
3888
3889 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
3890
3891 pollfd.fd = listener;
3892 pollfd.events = POLLIN | POLLOUT;
3893
3894 EXPECT_GT(poll(&pollfd, 1, -1), 0);
3895 EXPECT_EQ(pollfd.revents, POLLOUT);
3896
3897 EXPECT_EQ(req.data.nr, __NR_dup);
3898
3899 resp.id = req.id;
3900 resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
3901
3902 /*
3903 * Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
3904 * args be set to 0.
3905 */
3906 resp.error = 0;
3907 resp.val = USER_NOTIF_MAGIC;
3908 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3909 EXPECT_EQ(errno, EINVAL);
3910
3911 resp.error = USER_NOTIF_MAGIC;
3912 resp.val = 0;
3913 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
3914 EXPECT_EQ(errno, EINVAL);
3915
3916 resp.error = 0;
3917 resp.val = 0;
3918 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
3919 if (errno == EINVAL)
3920 SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
3921 }
3922
3923 skip:
3924 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3925 EXPECT_EQ(true, WIFEXITED(status));
3926 EXPECT_EQ(0, WEXITSTATUS(status)) {
3927 if (WEXITSTATUS(status) == 2) {
3928 SKIP(return, "Kernel does not support kcmp() syscall");
3929 return;
3930 }
3931 }
3932 }
3933
TEST(user_notification_filter_empty)3934 TEST(user_notification_filter_empty)
3935 {
3936 pid_t pid;
3937 long ret;
3938 int status;
3939 struct pollfd pollfd;
3940 struct __clone_args args = {
3941 .flags = CLONE_FILES,
3942 .exit_signal = SIGCHLD,
3943 };
3944
3945 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3946 ASSERT_EQ(0, ret) {
3947 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
3948 }
3949
3950 if (__NR_clone3 < 0)
3951 SKIP(return, "Test not built with clone3 support");
3952
3953 pid = sys_clone3(&args, sizeof(args));
3954 ASSERT_GE(pid, 0);
3955
3956 if (pid == 0) {
3957 int listener;
3958
3959 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
3960 if (listener < 0)
3961 _exit(EXIT_FAILURE);
3962
3963 if (dup2(listener, 200) != 200)
3964 _exit(EXIT_FAILURE);
3965
3966 close(listener);
3967
3968 _exit(EXIT_SUCCESS);
3969 }
3970
3971 EXPECT_EQ(waitpid(pid, &status, 0), pid);
3972 EXPECT_EQ(true, WIFEXITED(status));
3973 EXPECT_EQ(0, WEXITSTATUS(status));
3974
3975 /*
3976 * The seccomp filter has become unused so we should be notified once
3977 * the kernel gets around to cleaning up task struct.
3978 */
3979 pollfd.fd = 200;
3980 pollfd.events = POLLHUP;
3981
3982 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
3983 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
3984 }
3985
TEST(user_ioctl_notification_filter_empty)3986 TEST(user_ioctl_notification_filter_empty)
3987 {
3988 pid_t pid;
3989 long ret;
3990 int status, p[2];
3991 struct __clone_args args = {
3992 .flags = CLONE_FILES,
3993 .exit_signal = SIGCHLD,
3994 };
3995 struct seccomp_notif req = {};
3996
3997 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
3998 ASSERT_EQ(0, ret) {
3999 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4000 }
4001
4002 if (__NR_clone3 < 0)
4003 SKIP(return, "Test not built with clone3 support");
4004
4005 ASSERT_EQ(0, pipe(p));
4006
4007 pid = sys_clone3(&args, sizeof(args));
4008 ASSERT_GE(pid, 0);
4009
4010 if (pid == 0) {
4011 int listener;
4012
4013 listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
4014 if (listener < 0)
4015 _exit(EXIT_FAILURE);
4016
4017 if (dup2(listener, 200) != 200)
4018 _exit(EXIT_FAILURE);
4019 close(p[1]);
4020 close(listener);
4021 sleep(1);
4022
4023 _exit(EXIT_SUCCESS);
4024 }
4025 if (read(p[0], &status, 1) != 0)
4026 _exit(EXIT_SUCCESS);
4027 close(p[0]);
4028 /*
4029 * The seccomp filter has become unused so we should be notified once
4030 * the kernel gets around to cleaning up task struct.
4031 */
4032 EXPECT_EQ(ioctl(200, SECCOMP_IOCTL_NOTIF_RECV, &req), -1);
4033 EXPECT_EQ(errno, ENOENT);
4034
4035 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4036 EXPECT_EQ(true, WIFEXITED(status));
4037 EXPECT_EQ(0, WEXITSTATUS(status));
4038 }
4039
do_thread(void * data)4040 static void *do_thread(void *data)
4041 {
4042 return NULL;
4043 }
4044
TEST(user_notification_filter_empty_threaded)4045 TEST(user_notification_filter_empty_threaded)
4046 {
4047 pid_t pid;
4048 long ret;
4049 int status;
4050 struct pollfd pollfd;
4051 struct __clone_args args = {
4052 .flags = CLONE_FILES,
4053 .exit_signal = SIGCHLD,
4054 };
4055
4056 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4057 ASSERT_EQ(0, ret) {
4058 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4059 }
4060
4061 if (__NR_clone3 < 0)
4062 SKIP(return, "Test not built with clone3 support");
4063
4064 pid = sys_clone3(&args, sizeof(args));
4065 ASSERT_GE(pid, 0);
4066
4067 if (pid == 0) {
4068 pid_t pid1, pid2;
4069 int listener, status;
4070 pthread_t thread;
4071
4072 listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
4073 if (listener < 0)
4074 _exit(EXIT_FAILURE);
4075
4076 if (dup2(listener, 200) != 200)
4077 _exit(EXIT_FAILURE);
4078
4079 close(listener);
4080
4081 pid1 = fork();
4082 if (pid1 < 0)
4083 _exit(EXIT_FAILURE);
4084
4085 if (pid1 == 0)
4086 _exit(EXIT_SUCCESS);
4087
4088 pid2 = fork();
4089 if (pid2 < 0)
4090 _exit(EXIT_FAILURE);
4091
4092 if (pid2 == 0)
4093 _exit(EXIT_SUCCESS);
4094
4095 if (pthread_create(&thread, NULL, do_thread, NULL) ||
4096 pthread_join(thread, NULL))
4097 _exit(EXIT_FAILURE);
4098
4099 if (pthread_create(&thread, NULL, do_thread, NULL) ||
4100 pthread_join(thread, NULL))
4101 _exit(EXIT_FAILURE);
4102
4103 if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) ||
4104 WEXITSTATUS(status))
4105 _exit(EXIT_FAILURE);
4106
4107 if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) ||
4108 WEXITSTATUS(status))
4109 _exit(EXIT_FAILURE);
4110
4111 exit(EXIT_SUCCESS);
4112 }
4113
4114 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4115 EXPECT_EQ(true, WIFEXITED(status));
4116 EXPECT_EQ(0, WEXITSTATUS(status));
4117
4118 /*
4119 * The seccomp filter has become unused so we should be notified once
4120 * the kernel gets around to cleaning up task struct.
4121 */
4122 pollfd.fd = 200;
4123 pollfd.events = POLLHUP;
4124
4125 EXPECT_GT(poll(&pollfd, 1, 2000), 0);
4126 EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
4127 }
4128
4129
get_next_fd(int prev_fd)4130 int get_next_fd(int prev_fd)
4131 {
4132 for (int i = prev_fd + 1; i < FD_SETSIZE; ++i) {
4133 if (fcntl(i, F_GETFD) == -1)
4134 return i;
4135 }
4136 _exit(EXIT_FAILURE);
4137 }
4138
TEST(user_notification_addfd)4139 TEST(user_notification_addfd)
4140 {
4141 pid_t pid;
4142 long ret;
4143 int status, listener, memfd, fd, nextfd;
4144 struct seccomp_notif_addfd addfd = {};
4145 struct seccomp_notif_addfd_small small = {};
4146 struct seccomp_notif_addfd_big big = {};
4147 struct seccomp_notif req = {};
4148 struct seccomp_notif_resp resp = {};
4149 /* 100 ms */
4150 struct timespec delay = { .tv_nsec = 100000000 };
4151
4152 /* There may be arbitrary already-open fds at test start. */
4153 memfd = memfd_create("test", 0);
4154 ASSERT_GE(memfd, 0);
4155 nextfd = get_next_fd(memfd);
4156
4157 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4158 ASSERT_EQ(0, ret) {
4159 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4160 }
4161
4162 /* fd: 4 */
4163 /* Check that the basic notification machinery works */
4164 listener = user_notif_syscall(__NR_getppid,
4165 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4166 ASSERT_EQ(listener, nextfd);
4167 nextfd = get_next_fd(nextfd);
4168
4169 pid = fork();
4170 ASSERT_GE(pid, 0);
4171
4172 if (pid == 0) {
4173 /* fds will be added and this value is expected */
4174 if (syscall(__NR_getppid) != USER_NOTIF_MAGIC)
4175 exit(1);
4176
4177 /* Atomic addfd+send is received here. Check it is a valid fd */
4178 if (fcntl(syscall(__NR_getppid), F_GETFD) == -1)
4179 exit(1);
4180
4181 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4182 }
4183
4184 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4185
4186 addfd.srcfd = memfd;
4187 addfd.newfd = 0;
4188 addfd.id = req.id;
4189 addfd.flags = 0x0;
4190
4191 /* Verify bad newfd_flags cannot be set */
4192 addfd.newfd_flags = ~O_CLOEXEC;
4193 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4194 EXPECT_EQ(errno, EINVAL);
4195 addfd.newfd_flags = O_CLOEXEC;
4196
4197 /* Verify bad flags cannot be set */
4198 addfd.flags = 0xff;
4199 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4200 EXPECT_EQ(errno, EINVAL);
4201 addfd.flags = 0;
4202
4203 /* Verify that remote_fd cannot be set without setting flags */
4204 addfd.newfd = 1;
4205 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4206 EXPECT_EQ(errno, EINVAL);
4207 addfd.newfd = 0;
4208
4209 /* Verify small size cannot be set */
4210 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1);
4211 EXPECT_EQ(errno, EINVAL);
4212
4213 /* Verify we can't send bits filled in unknown buffer area */
4214 memset(&big, 0xAA, sizeof(big));
4215 big.addfd = addfd;
4216 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1);
4217 EXPECT_EQ(errno, E2BIG);
4218
4219
4220 /* Verify we can set an arbitrary remote fd */
4221 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4222 EXPECT_EQ(fd, nextfd);
4223 nextfd = get_next_fd(nextfd);
4224 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4225
4226 /* Verify we can set an arbitrary remote fd with large size */
4227 memset(&big, 0x0, sizeof(big));
4228 big.addfd = addfd;
4229 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
4230 EXPECT_EQ(fd, nextfd);
4231 nextfd = get_next_fd(nextfd);
4232
4233 /* Verify we can set a specific remote fd */
4234 addfd.newfd = 42;
4235 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4236 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4237 EXPECT_EQ(fd, 42);
4238 EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4239
4240 /* Resume syscall */
4241 resp.id = req.id;
4242 resp.error = 0;
4243 resp.val = USER_NOTIF_MAGIC;
4244 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4245
4246 /*
4247 * This sets the ID of the ADD FD to the last request plus 1. The
4248 * notification ID increments 1 per notification.
4249 */
4250 addfd.id = req.id + 1;
4251
4252 /* This spins until the underlying notification is generated */
4253 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4254 errno != -EINPROGRESS)
4255 nanosleep(&delay, NULL);
4256
4257 memset(&req, 0, sizeof(req));
4258 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4259 ASSERT_EQ(addfd.id, req.id);
4260
4261 /* Verify we can do an atomic addfd and send */
4262 addfd.newfd = 0;
4263 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4264 fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
4265 /*
4266 * Child has earlier "low" fds and now 42, so we expect the next
4267 * lowest available fd to be assigned here.
4268 */
4269 EXPECT_EQ(fd, nextfd);
4270 nextfd = get_next_fd(nextfd);
4271 ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
4272
4273 /*
4274 * This sets the ID of the ADD FD to the last request plus 1. The
4275 * notification ID increments 1 per notification.
4276 */
4277 addfd.id = req.id + 1;
4278
4279 /* This spins until the underlying notification is generated */
4280 while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
4281 errno != -EINPROGRESS)
4282 nanosleep(&delay, NULL);
4283
4284 memset(&req, 0, sizeof(req));
4285 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4286 ASSERT_EQ(addfd.id, req.id);
4287
4288 resp.id = req.id;
4289 resp.error = 0;
4290 resp.val = USER_NOTIF_MAGIC;
4291 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4292
4293 /* Wait for child to finish. */
4294 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4295 EXPECT_EQ(true, WIFEXITED(status));
4296 EXPECT_EQ(0, WEXITSTATUS(status));
4297
4298 close(memfd);
4299 }
4300
TEST(user_notification_addfd_rlimit)4301 TEST(user_notification_addfd_rlimit)
4302 {
4303 pid_t pid;
4304 long ret;
4305 int status, listener, memfd;
4306 struct seccomp_notif_addfd addfd = {};
4307 struct seccomp_notif req = {};
4308 struct seccomp_notif_resp resp = {};
4309 const struct rlimit lim = {
4310 .rlim_cur = 0,
4311 .rlim_max = 0,
4312 };
4313
4314 memfd = memfd_create("test", 0);
4315 ASSERT_GE(memfd, 0);
4316
4317 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4318 ASSERT_EQ(0, ret) {
4319 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4320 }
4321
4322 /* Check that the basic notification machinery works */
4323 listener = user_notif_syscall(__NR_getppid,
4324 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4325 ASSERT_GE(listener, 0);
4326
4327 pid = fork();
4328 ASSERT_GE(pid, 0);
4329
4330 if (pid == 0)
4331 exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
4332
4333
4334 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4335
4336 ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0);
4337
4338 addfd.srcfd = memfd;
4339 addfd.newfd_flags = O_CLOEXEC;
4340 addfd.newfd = 0;
4341 addfd.id = req.id;
4342 addfd.flags = 0;
4343
4344 /* Should probably spot check /proc/sys/fs/file-nr */
4345 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4346 EXPECT_EQ(errno, EMFILE);
4347
4348 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4349 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4350 EXPECT_EQ(errno, EMFILE);
4351
4352 addfd.newfd = 100;
4353 addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
4354 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
4355 EXPECT_EQ(errno, EBADF);
4356
4357 resp.id = req.id;
4358 resp.error = 0;
4359 resp.val = USER_NOTIF_MAGIC;
4360
4361 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4362
4363 /* Wait for child to finish. */
4364 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4365 EXPECT_EQ(true, WIFEXITED(status));
4366 EXPECT_EQ(0, WEXITSTATUS(status));
4367
4368 close(memfd);
4369 }
4370
4371 #ifndef SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP
4372 #define SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP (1UL << 0)
4373 #define SECCOMP_IOCTL_NOTIF_SET_FLAGS SECCOMP_IOW(4, __u64)
4374 #endif
4375
TEST(user_notification_sync)4376 TEST(user_notification_sync)
4377 {
4378 struct seccomp_notif req = {};
4379 struct seccomp_notif_resp resp = {};
4380 int status, listener;
4381 pid_t pid;
4382 long ret;
4383
4384 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4385 ASSERT_EQ(0, ret) {
4386 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4387 }
4388
4389 listener = user_notif_syscall(__NR_getppid,
4390 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4391 ASSERT_GE(listener, 0);
4392
4393 /* Try to set invalid flags. */
4394 EXPECT_SYSCALL_RETURN(-EINVAL,
4395 ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_FLAGS, 0xffffffff, 0));
4396
4397 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SET_FLAGS,
4398 SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP, 0), 0);
4399
4400 pid = fork();
4401 ASSERT_GE(pid, 0);
4402 if (pid == 0) {
4403 ret = syscall(__NR_getppid);
4404 ASSERT_EQ(ret, USER_NOTIF_MAGIC) {
4405 _exit(1);
4406 }
4407 _exit(0);
4408 }
4409
4410 req.pid = 0;
4411 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4412
4413 ASSERT_EQ(req.data.nr, __NR_getppid);
4414
4415 resp.id = req.id;
4416 resp.error = 0;
4417 resp.val = USER_NOTIF_MAGIC;
4418 resp.flags = 0;
4419 ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4420
4421 ASSERT_EQ(waitpid(pid, &status, 0), pid);
4422 ASSERT_EQ(status, 0);
4423 }
4424
4425
4426 /* Make sure PTRACE_O_SUSPEND_SECCOMP requires CAP_SYS_ADMIN. */
FIXTURE(O_SUSPEND_SECCOMP)4427 FIXTURE(O_SUSPEND_SECCOMP) {
4428 pid_t pid;
4429 };
4430
FIXTURE_SETUP(O_SUSPEND_SECCOMP)4431 FIXTURE_SETUP(O_SUSPEND_SECCOMP)
4432 {
4433 ERRNO_FILTER(block_read, E2BIG);
4434 cap_value_t cap_list[] = { CAP_SYS_ADMIN };
4435 cap_t caps;
4436
4437 self->pid = 0;
4438
4439 /* make sure we don't have CAP_SYS_ADMIN */
4440 caps = cap_get_proc();
4441 ASSERT_NE(NULL, caps);
4442 ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, cap_list, CAP_CLEAR));
4443 ASSERT_EQ(0, cap_set_proc(caps));
4444 cap_free(caps);
4445
4446 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
4447 ASSERT_EQ(0, prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_block_read));
4448
4449 self->pid = fork();
4450 ASSERT_GE(self->pid, 0);
4451
4452 if (self->pid == 0) {
4453 while (1)
4454 pause();
4455 _exit(127);
4456 }
4457 }
4458
FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP)4459 FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP)
4460 {
4461 if (self->pid)
4462 kill(self->pid, SIGKILL);
4463 }
4464
TEST_F(O_SUSPEND_SECCOMP,setoptions)4465 TEST_F(O_SUSPEND_SECCOMP, setoptions)
4466 {
4467 int wstatus;
4468
4469 ASSERT_EQ(0, ptrace(PTRACE_ATTACH, self->pid, NULL, 0));
4470 ASSERT_EQ(self->pid, wait(&wstatus));
4471 ASSERT_EQ(-1, ptrace(PTRACE_SETOPTIONS, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP));
4472 if (errno == EINVAL)
4473 SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
4474 ASSERT_EQ(EPERM, errno);
4475 }
4476
TEST_F(O_SUSPEND_SECCOMP,seize)4477 TEST_F(O_SUSPEND_SECCOMP, seize)
4478 {
4479 int ret;
4480
4481 ret = ptrace(PTRACE_SEIZE, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP);
4482 ASSERT_EQ(-1, ret);
4483 if (errno == EINVAL)
4484 SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
4485 ASSERT_EQ(EPERM, errno);
4486 }
4487
4488 /*
4489 * get_nth - Get the nth, space separated entry in a file.
4490 *
4491 * Returns the length of the read field.
4492 * Throws error if field is zero-lengthed.
4493 */
get_nth(struct __test_metadata * _metadata,const char * path,const unsigned int position,char ** entry)4494 static ssize_t get_nth(struct __test_metadata *_metadata, const char *path,
4495 const unsigned int position, char **entry)
4496 {
4497 char *line = NULL;
4498 unsigned int i;
4499 ssize_t nread;
4500 size_t len = 0;
4501 FILE *f;
4502
4503 f = fopen(path, "r");
4504 ASSERT_NE(f, NULL) {
4505 TH_LOG("Could not open %s: %s", path, strerror(errno));
4506 }
4507
4508 for (i = 0; i < position; i++) {
4509 nread = getdelim(&line, &len, ' ', f);
4510 ASSERT_GE(nread, 0) {
4511 TH_LOG("Failed to read %d entry in file %s", i, path);
4512 }
4513 }
4514 fclose(f);
4515
4516 ASSERT_GT(nread, 0) {
4517 TH_LOG("Entry in file %s had zero length", path);
4518 }
4519
4520 *entry = line;
4521 return nread - 1;
4522 }
4523
4524 /* For a given PID, get the task state (D, R, etc...) */
get_proc_stat(struct __test_metadata * _metadata,pid_t pid)4525 static char get_proc_stat(struct __test_metadata *_metadata, pid_t pid)
4526 {
4527 char proc_path[100] = {0};
4528 char status;
4529 char *line;
4530
4531 snprintf(proc_path, sizeof(proc_path), "/proc/%d/stat", pid);
4532 ASSERT_EQ(get_nth(_metadata, proc_path, 3, &line), 1);
4533
4534 status = *line;
4535 free(line);
4536
4537 return status;
4538 }
4539
TEST(user_notification_fifo)4540 TEST(user_notification_fifo)
4541 {
4542 struct seccomp_notif_resp resp = {};
4543 struct seccomp_notif req = {};
4544 int i, status, listener;
4545 pid_t pid, pids[3];
4546 __u64 baseid;
4547 long ret;
4548 /* 100 ms */
4549 struct timespec delay = { .tv_nsec = 100000000 };
4550
4551 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4552 ASSERT_EQ(0, ret) {
4553 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4554 }
4555
4556 /* Setup a listener */
4557 listener = user_notif_syscall(__NR_getppid,
4558 SECCOMP_FILTER_FLAG_NEW_LISTENER);
4559 ASSERT_GE(listener, 0);
4560
4561 pid = fork();
4562 ASSERT_GE(pid, 0);
4563
4564 if (pid == 0) {
4565 ret = syscall(__NR_getppid);
4566 exit(ret != USER_NOTIF_MAGIC);
4567 }
4568
4569 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4570 baseid = req.id + 1;
4571
4572 resp.id = req.id;
4573 resp.error = 0;
4574 resp.val = USER_NOTIF_MAGIC;
4575
4576 /* check that we make sure flags == 0 */
4577 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4578
4579 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4580 EXPECT_EQ(true, WIFEXITED(status));
4581 EXPECT_EQ(0, WEXITSTATUS(status));
4582
4583 /* Start children, and generate notifications */
4584 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4585 pid = fork();
4586 if (pid == 0) {
4587 ret = syscall(__NR_getppid);
4588 exit(ret != USER_NOTIF_MAGIC);
4589 }
4590 pids[i] = pid;
4591 }
4592
4593 /* This spins until all of the children are sleeping */
4594 restart_wait:
4595 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4596 if (get_proc_stat(_metadata, pids[i]) != 'S') {
4597 nanosleep(&delay, NULL);
4598 goto restart_wait;
4599 }
4600 }
4601
4602 /* Read the notifications in order (and respond) */
4603 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4604 memset(&req, 0, sizeof(req));
4605 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4606 EXPECT_EQ(req.id, baseid + i);
4607 resp.id = req.id;
4608 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4609 }
4610
4611 /* Make sure notifications were received */
4612 for (i = 0; i < ARRAY_SIZE(pids); i++) {
4613 EXPECT_EQ(waitpid(pids[i], &status, 0), pids[i]);
4614 EXPECT_EQ(true, WIFEXITED(status));
4615 EXPECT_EQ(0, WEXITSTATUS(status));
4616 }
4617 }
4618
4619 /* get_proc_syscall - Get the syscall in progress for a given pid
4620 *
4621 * Returns the current syscall number for a given process
4622 * Returns -1 if not in syscall (running or blocked)
4623 */
get_proc_syscall(struct __test_metadata * _metadata,int pid)4624 static long get_proc_syscall(struct __test_metadata *_metadata, int pid)
4625 {
4626 char proc_path[100] = {0};
4627 long ret = -1;
4628 ssize_t nread;
4629 char *line;
4630
4631 snprintf(proc_path, sizeof(proc_path), "/proc/%d/syscall", pid);
4632 nread = get_nth(_metadata, proc_path, 1, &line);
4633 ASSERT_GT(nread, 0);
4634
4635 if (!strncmp("running", line, MIN(7, nread)))
4636 ret = strtol(line, NULL, 16);
4637
4638 free(line);
4639 return ret;
4640 }
4641
4642 /* Ensure non-fatal signals prior to receive are unmodified */
TEST(user_notification_wait_killable_pre_notification)4643 TEST(user_notification_wait_killable_pre_notification)
4644 {
4645 struct sigaction new_action = {
4646 .sa_handler = signal_handler,
4647 };
4648 int listener, status, sk_pair[2];
4649 pid_t pid;
4650 long ret;
4651 char c;
4652 /* 100 ms */
4653 struct timespec delay = { .tv_nsec = 100000000 };
4654
4655 ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
4656
4657 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4658 ASSERT_EQ(0, ret)
4659 {
4660 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4661 }
4662
4663 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
4664
4665 listener = user_notif_syscall(
4666 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4667 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4668 ASSERT_GE(listener, 0);
4669
4670 /*
4671 * Check that we can kill the process with SIGUSR1 prior to receiving
4672 * the notification. SIGUSR1 is wired up to a custom signal handler,
4673 * and make sure it gets called.
4674 */
4675 pid = fork();
4676 ASSERT_GE(pid, 0);
4677
4678 if (pid == 0) {
4679 close(sk_pair[0]);
4680 handled = sk_pair[1];
4681
4682 /* Setup the non-fatal sigaction without SA_RESTART */
4683 if (sigaction(SIGUSR1, &new_action, NULL)) {
4684 perror("sigaction");
4685 exit(1);
4686 }
4687
4688 ret = syscall(__NR_getppid);
4689 /* Make sure we got a return from a signal interruption */
4690 exit(ret != -1 || errno != EINTR);
4691 }
4692
4693 /*
4694 * Make sure we've gotten to the seccomp user notification wait
4695 * from getppid prior to sending any signals
4696 */
4697 while (get_proc_syscall(_metadata, pid) != __NR_getppid &&
4698 get_proc_stat(_metadata, pid) != 'S')
4699 nanosleep(&delay, NULL);
4700
4701 /* Send non-fatal kill signal */
4702 EXPECT_EQ(kill(pid, SIGUSR1), 0);
4703
4704 /* wait for process to exit (exit checks for EINTR) */
4705 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4706 EXPECT_EQ(true, WIFEXITED(status));
4707 EXPECT_EQ(0, WEXITSTATUS(status));
4708
4709 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
4710 }
4711
4712 /* Ensure non-fatal signals after receive are blocked */
TEST(user_notification_wait_killable)4713 TEST(user_notification_wait_killable)
4714 {
4715 struct sigaction new_action = {
4716 .sa_handler = signal_handler,
4717 };
4718 struct seccomp_notif_resp resp = {};
4719 struct seccomp_notif req = {};
4720 int listener, status, sk_pair[2];
4721 pid_t pid;
4722 long ret;
4723 char c;
4724 /* 100 ms */
4725 struct timespec delay = { .tv_nsec = 100000000 };
4726
4727 ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
4728
4729 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4730 ASSERT_EQ(0, ret)
4731 {
4732 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4733 }
4734
4735 ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
4736
4737 listener = user_notif_syscall(
4738 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4739 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4740 ASSERT_GE(listener, 0);
4741
4742 pid = fork();
4743 ASSERT_GE(pid, 0);
4744
4745 if (pid == 0) {
4746 close(sk_pair[0]);
4747 handled = sk_pair[1];
4748
4749 /* Setup the sigaction without SA_RESTART */
4750 if (sigaction(SIGUSR1, &new_action, NULL)) {
4751 perror("sigaction");
4752 exit(1);
4753 }
4754
4755 /* Make sure that the syscall is completed (no EINTR) */
4756 ret = syscall(__NR_getppid);
4757 exit(ret != USER_NOTIF_MAGIC);
4758 }
4759
4760 /*
4761 * Get the notification, to make move the notifying process into a
4762 * non-preemptible (TASK_KILLABLE) state.
4763 */
4764 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4765 /* Send non-fatal kill signal */
4766 EXPECT_EQ(kill(pid, SIGUSR1), 0);
4767
4768 /*
4769 * Make sure the task enters moves to TASK_KILLABLE by waiting for
4770 * D (Disk Sleep) state after receiving non-fatal signal.
4771 */
4772 while (get_proc_stat(_metadata, pid) != 'D')
4773 nanosleep(&delay, NULL);
4774
4775 resp.id = req.id;
4776 resp.val = USER_NOTIF_MAGIC;
4777 /* Make sure the notification is found and able to be replied to */
4778 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
4779
4780 /*
4781 * Make sure that the signal handler does get called once we're back in
4782 * userspace.
4783 */
4784 EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
4785 /* wait for process to exit (exit checks for USER_NOTIF_MAGIC) */
4786 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4787 EXPECT_EQ(true, WIFEXITED(status));
4788 EXPECT_EQ(0, WEXITSTATUS(status));
4789 }
4790
4791 /* Ensure fatal signals after receive are not blocked */
TEST(user_notification_wait_killable_fatal)4792 TEST(user_notification_wait_killable_fatal)
4793 {
4794 struct seccomp_notif req = {};
4795 int listener, status;
4796 pid_t pid;
4797 long ret;
4798 /* 100 ms */
4799 struct timespec delay = { .tv_nsec = 100000000 };
4800
4801 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4802 ASSERT_EQ(0, ret)
4803 {
4804 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4805 }
4806
4807 listener = user_notif_syscall(
4808 __NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4809 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4810 ASSERT_GE(listener, 0);
4811
4812 pid = fork();
4813 ASSERT_GE(pid, 0);
4814
4815 if (pid == 0) {
4816 /* This should never complete as it should get a SIGTERM */
4817 syscall(__NR_getppid);
4818 exit(1);
4819 }
4820
4821 while (get_proc_stat(_metadata, pid) != 'S')
4822 nanosleep(&delay, NULL);
4823
4824 /*
4825 * Get the notification, to make move the notifying process into a
4826 * non-preemptible (TASK_KILLABLE) state.
4827 */
4828 EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
4829 /* Kill the process with a fatal signal */
4830 EXPECT_EQ(kill(pid, SIGTERM), 0);
4831
4832 /*
4833 * Wait for the process to exit, and make sure the process terminated
4834 * due to the SIGTERM signal.
4835 */
4836 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4837 EXPECT_EQ(true, WIFSIGNALED(status));
4838 EXPECT_EQ(SIGTERM, WTERMSIG(status));
4839 }
4840
4841 /* Ensure signals after the reply do not interrupt */
TEST(user_notification_wait_killable_after_reply)4842 TEST(user_notification_wait_killable_after_reply)
4843 {
4844 int i, max_iter = 100000;
4845 int listener, status;
4846 int pipe_fds[2];
4847 pid_t pid;
4848 long ret;
4849
4850 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
4851 ASSERT_EQ(0, ret)
4852 {
4853 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
4854 }
4855
4856 listener = user_notif_syscall(
4857 __NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER |
4858 SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
4859 ASSERT_GE(listener, 0);
4860
4861 /*
4862 * Used to count invocations. One token is transferred from the child
4863 * to the parent per syscall invocation, the parent tries to take
4864 * one token per successful RECV. If the syscall is restarted after
4865 * RECV the parent will try to get two tokens while the child only
4866 * provided one.
4867 */
4868 ASSERT_EQ(pipe(pipe_fds), 0);
4869
4870 pid = fork();
4871 ASSERT_GE(pid, 0);
4872
4873 if (pid == 0) {
4874 struct sigaction new_action = {
4875 .sa_handler = signal_handler_nop,
4876 .sa_flags = SA_RESTART,
4877 };
4878 struct itimerval timer = {
4879 .it_value = { .tv_usec = 1000 },
4880 .it_interval = { .tv_usec = 1000 },
4881 };
4882 char c = 'a';
4883
4884 close(pipe_fds[0]);
4885
4886 /* Setup the sigaction with SA_RESTART */
4887 if (sigaction(SIGALRM, &new_action, NULL)) {
4888 perror("sigaction");
4889 exit(1);
4890 }
4891
4892 /*
4893 * Kill with SIGALRM repeatedly, to try to hit the race when
4894 * handling the syscall.
4895 */
4896 if (setitimer(ITIMER_REAL, &timer, NULL) < 0)
4897 perror("setitimer");
4898
4899 for (i = 0; i < max_iter; ++i) {
4900 int fd;
4901
4902 /* Send one token per iteration to catch repeats. */
4903 if (write(pipe_fds[1], &c, sizeof(c)) != 1) {
4904 perror("write");
4905 exit(1);
4906 }
4907
4908 fd = syscall(__NR_dup, 0);
4909 if (fd < 0) {
4910 perror("dup");
4911 exit(1);
4912 }
4913 close(fd);
4914 }
4915
4916 exit(0);
4917 }
4918
4919 close(pipe_fds[1]);
4920
4921 for (i = 0; i < max_iter; ++i) {
4922 struct seccomp_notif req = {};
4923 struct seccomp_notif_addfd addfd = {};
4924 struct pollfd pfd = {
4925 .fd = pipe_fds[0],
4926 .events = POLLIN,
4927 };
4928 char c;
4929
4930 /*
4931 * Try to receive one token. If it failed, one child syscall
4932 * was restarted after RECV and needed to be handled twice.
4933 */
4934 ASSERT_EQ(poll(&pfd, 1, 1000), 1)
4935 kill(pid, SIGKILL);
4936
4937 ASSERT_EQ(read(pipe_fds[0], &c, sizeof(c)), 1)
4938 kill(pid, SIGKILL);
4939
4940 /*
4941 * Get the notification, reply to it as fast as possible to test
4942 * whether the child wrongly skips going into the non-preemptible
4943 * (TASK_KILLABLE) state.
4944 */
4945 do
4946 ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
4947 while (ret < 0 && errno == ENOENT); /* Accept interruptions before RECV */
4948 ASSERT_EQ(ret, 0)
4949 kill(pid, SIGKILL);
4950
4951 addfd.id = req.id;
4952 addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
4953 addfd.srcfd = 0;
4954 ASSERT_GE(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), 0)
4955 kill(pid, SIGKILL);
4956 }
4957
4958 /*
4959 * Wait for the process to exit, and make sure the process terminated
4960 * with a zero exit code..
4961 */
4962 EXPECT_EQ(waitpid(pid, &status, 0), pid);
4963 EXPECT_EQ(true, WIFEXITED(status));
4964 EXPECT_EQ(0, WEXITSTATUS(status));
4965 }
4966
4967 struct tsync_vs_thread_leader_args {
4968 pthread_t leader;
4969 };
4970
tsync_vs_dead_thread_leader_sibling(void * _args)4971 static void *tsync_vs_dead_thread_leader_sibling(void *_args)
4972 {
4973 struct sock_filter allow_filter[] = {
4974 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
4975 };
4976 struct sock_fprog allow_prog = {
4977 .len = (unsigned short)ARRAY_SIZE(allow_filter),
4978 .filter = allow_filter,
4979 };
4980 struct tsync_vs_thread_leader_args *args = _args;
4981 void *retval;
4982 long ret;
4983
4984 ret = pthread_join(args->leader, &retval);
4985 if (ret)
4986 exit(1);
4987 if (retval != _args)
4988 exit(2);
4989 ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, &allow_prog);
4990 if (ret)
4991 exit(3);
4992
4993 exit(0);
4994 }
4995
4996 /*
4997 * Ensure that a dead thread leader doesn't prevent installing new filters with
4998 * SECCOMP_FILTER_FLAG_TSYNC from other threads.
4999 */
TEST(tsync_vs_dead_thread_leader)5000 TEST(tsync_vs_dead_thread_leader)
5001 {
5002 int status;
5003 pid_t pid;
5004 long ret;
5005
5006 ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
5007 ASSERT_EQ(0, ret) {
5008 TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
5009 }
5010
5011 pid = fork();
5012 ASSERT_GE(pid, 0);
5013
5014 if (pid == 0) {
5015 struct sock_filter allow_filter[] = {
5016 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
5017 };
5018 struct sock_fprog allow_prog = {
5019 .len = (unsigned short)ARRAY_SIZE(allow_filter),
5020 .filter = allow_filter,
5021 };
5022 struct tsync_vs_thread_leader_args *args;
5023 pthread_t sibling;
5024
5025 args = malloc(sizeof(*args));
5026 ASSERT_NE(NULL, args);
5027 args->leader = pthread_self();
5028
5029 ret = pthread_create(&sibling, NULL,
5030 tsync_vs_dead_thread_leader_sibling, args);
5031 ASSERT_EQ(0, ret);
5032
5033 /* Install a new filter just to the leader thread. */
5034 ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
5035 ASSERT_EQ(0, ret);
5036 pthread_exit(args);
5037 exit(1);
5038 }
5039
5040 EXPECT_EQ(pid, waitpid(pid, &status, 0));
5041 EXPECT_EQ(0, status);
5042 }
5043
5044 #ifdef __x86_64__
5045
5046 /*
5047 * We need naked probed_uprobe function. Using __nocf_check
5048 * check to skip possible endbr64 instruction and ignoring
5049 * -Wattributes, otherwise the compilation might fail.
5050 */
5051 #pragma GCC diagnostic push
5052 #pragma GCC diagnostic ignored "-Wattributes"
5053
probed_uprobe(void)5054 __naked __nocf_check noinline int probed_uprobe(void)
5055 {
5056 /*
5057 * Optimized uprobe is possible only on top of nop5 instruction.
5058 */
5059 asm volatile (" \n"
5060 ".byte 0x0f, 0x1f, 0x44, 0x00, 0x00 \n"
5061 "ret \n"
5062 );
5063 }
5064 #pragma GCC diagnostic pop
5065
5066 #else
probed_uprobe(void)5067 noinline int probed_uprobe(void)
5068 {
5069 return 1;
5070 }
5071 #endif
5072
probed_uretprobe(void)5073 noinline int probed_uretprobe(void)
5074 {
5075 return 1;
5076 }
5077
parse_uint_from_file(const char * file,const char * fmt)5078 static int parse_uint_from_file(const char *file, const char *fmt)
5079 {
5080 int err = -1, ret;
5081 FILE *f;
5082
5083 f = fopen(file, "re");
5084 if (f) {
5085 err = fscanf(f, fmt, &ret);
5086 fclose(f);
5087 }
5088 return err == 1 ? ret : err;
5089 }
5090
determine_uprobe_perf_type(void)5091 static int determine_uprobe_perf_type(void)
5092 {
5093 const char *file = "/sys/bus/event_source/devices/uprobe/type";
5094
5095 return parse_uint_from_file(file, "%d\n");
5096 }
5097
determine_uprobe_retprobe_bit(void)5098 static int determine_uprobe_retprobe_bit(void)
5099 {
5100 const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe";
5101
5102 return parse_uint_from_file(file, "config:%d\n");
5103 }
5104
get_uprobe_offset(const void * addr)5105 static ssize_t get_uprobe_offset(const void *addr)
5106 {
5107 size_t start, base, end;
5108 bool found = false;
5109 char buf[256];
5110 FILE *f;
5111
5112 f = fopen("/proc/self/maps", "r");
5113 if (!f)
5114 return -1;
5115
5116 while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) {
5117 if (buf[2] == 'x' && (uintptr_t)addr >= start && (uintptr_t)addr < end) {
5118 found = true;
5119 break;
5120 }
5121 }
5122 fclose(f);
5123 return found ? (uintptr_t)addr - start + base : -1;
5124 }
5125
FIXTURE(UPROBE)5126 FIXTURE(UPROBE) {
5127 int fd;
5128 };
5129
FIXTURE_VARIANT(UPROBE)5130 FIXTURE_VARIANT(UPROBE) {
5131 /*
5132 * All of the U(RET)PROBE behaviors can be tested with either
5133 * u(ret)probe attached or not
5134 */
5135 bool attach;
5136 /*
5137 * Test both uprobe and uretprobe.
5138 */
5139 bool uretprobe;
5140 };
5141
FIXTURE_VARIANT_ADD(UPROBE,not_attached)5142 FIXTURE_VARIANT_ADD(UPROBE, not_attached) {
5143 .attach = false,
5144 .uretprobe = false,
5145 };
5146
FIXTURE_VARIANT_ADD(UPROBE,uprobe_attached)5147 FIXTURE_VARIANT_ADD(UPROBE, uprobe_attached) {
5148 .attach = true,
5149 .uretprobe = false,
5150 };
5151
FIXTURE_VARIANT_ADD(UPROBE,uretprobe_attached)5152 FIXTURE_VARIANT_ADD(UPROBE, uretprobe_attached) {
5153 .attach = true,
5154 .uretprobe = true,
5155 };
5156
FIXTURE_SETUP(UPROBE)5157 FIXTURE_SETUP(UPROBE)
5158 {
5159 const size_t attr_sz = sizeof(struct perf_event_attr);
5160 struct perf_event_attr attr;
5161 ssize_t offset;
5162 int type, bit;
5163
5164 #if !defined(__NR_uprobe) || !defined(__NR_uretprobe)
5165 SKIP(return, "__NR_uprobe ot __NR_uretprobe syscalls not defined");
5166 #endif
5167
5168 if (!variant->attach)
5169 return;
5170
5171 memset(&attr, 0, attr_sz);
5172
5173 type = determine_uprobe_perf_type();
5174 ASSERT_GE(type, 0);
5175
5176 if (variant->uretprobe) {
5177 bit = determine_uprobe_retprobe_bit();
5178 ASSERT_GE(bit, 0);
5179 }
5180
5181 offset = get_uprobe_offset(variant->uretprobe ? probed_uretprobe : probed_uprobe);
5182 ASSERT_GE(offset, 0);
5183
5184 if (variant->uretprobe)
5185 attr.config |= 1 << bit;
5186 attr.size = attr_sz;
5187 attr.type = type;
5188 attr.config1 = ptr_to_u64("/proc/self/exe");
5189 attr.config2 = offset;
5190
5191 self->fd = syscall(__NR_perf_event_open, &attr,
5192 getpid() /* pid */, -1 /* cpu */, -1 /* group_fd */,
5193 PERF_FLAG_FD_CLOEXEC);
5194 }
5195
FIXTURE_TEARDOWN(UPROBE)5196 FIXTURE_TEARDOWN(UPROBE)
5197 {
5198 /* we could call close(self->fd), but we'd need extra filter for
5199 * that and since we are calling _exit right away..
5200 */
5201 }
5202
run_probed_with_filter(struct sock_fprog * prog)5203 static int run_probed_with_filter(struct sock_fprog *prog)
5204 {
5205 if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) ||
5206 seccomp(SECCOMP_SET_MODE_FILTER, 0, prog)) {
5207 return -1;
5208 }
5209
5210 /*
5211 * Uprobe is optimized after first hit, so let's hit twice.
5212 */
5213 probed_uprobe();
5214 probed_uprobe();
5215
5216 probed_uretprobe();
5217 return 0;
5218 }
5219
TEST_F(UPROBE,uprobe_default_allow)5220 TEST_F(UPROBE, uprobe_default_allow)
5221 {
5222 struct sock_filter filter[] = {
5223 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
5224 };
5225 struct sock_fprog prog = {
5226 .len = (unsigned short)ARRAY_SIZE(filter),
5227 .filter = filter,
5228 };
5229
5230 ASSERT_EQ(0, run_probed_with_filter(&prog));
5231 }
5232
TEST_F(UPROBE,uprobe_default_block)5233 TEST_F(UPROBE, uprobe_default_block)
5234 {
5235 struct sock_filter filter[] = {
5236 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
5237 offsetof(struct seccomp_data, nr)),
5238 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit_group, 1, 0),
5239 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
5240 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
5241 };
5242 struct sock_fprog prog = {
5243 .len = (unsigned short)ARRAY_SIZE(filter),
5244 .filter = filter,
5245 };
5246
5247 ASSERT_EQ(0, run_probed_with_filter(&prog));
5248 }
5249
TEST_F(UPROBE,uprobe_block_syscall)5250 TEST_F(UPROBE, uprobe_block_syscall)
5251 {
5252 struct sock_filter filter[] = {
5253 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
5254 offsetof(struct seccomp_data, nr)),
5255 #ifdef __NR_uprobe
5256 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_uprobe, 1, 2),
5257 #endif
5258 #ifdef __NR_uretprobe
5259 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_uretprobe, 0, 1),
5260 #endif
5261 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
5262 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
5263 };
5264 struct sock_fprog prog = {
5265 .len = (unsigned short)ARRAY_SIZE(filter),
5266 .filter = filter,
5267 };
5268
5269 ASSERT_EQ(0, run_probed_with_filter(&prog));
5270 }
5271
TEST_F(UPROBE,uprobe_default_block_with_syscall)5272 TEST_F(UPROBE, uprobe_default_block_with_syscall)
5273 {
5274 struct sock_filter filter[] = {
5275 BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
5276 offsetof(struct seccomp_data, nr)),
5277 #ifdef __NR_uprobe
5278 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_uprobe, 3, 0),
5279 #endif
5280 #ifdef __NR_uretprobe
5281 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_uretprobe, 2, 0),
5282 #endif
5283 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit_group, 1, 0),
5284 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
5285 BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
5286 };
5287 struct sock_fprog prog = {
5288 .len = (unsigned short)ARRAY_SIZE(filter),
5289 .filter = filter,
5290 };
5291
5292 ASSERT_EQ(0, run_probed_with_filter(&prog));
5293 }
5294
5295 /*
5296 * TODO:
5297 * - expand NNP testing
5298 * - better arch-specific TRACE and TRAP handlers.
5299 * - endianness checking when appropriate
5300 * - 64-bit arg prodding
5301 * - arch value testing (x86 modes especially)
5302 * - verify that FILTER_FLAG_LOG filters generate log messages
5303 * - verify that RET_LOG generates log messages
5304 */
5305
5306 TEST_HARNESS_MAIN
5307