1 // SPDX-License-Identifier: LGPL-2.1+
2 /*
3 * Copyright (C) International Business Machines Corp., 2007,2008
4 * Author(s): Steve French (sfrench@us.ibm.com)
5 * Copyright (C) 2020 Samsung Electronics Co., Ltd.
6 * Author(s): Namjae Jeon <linkinjeon@kernel.org>
7 */
8
9 #include <linux/fs.h>
10 #include <linux/slab.h>
11 #include <linux/string.h>
12 #include <linux/mnt_idmapping.h>
13
14 #include "smbacl.h"
15 #include "smb_common.h"
16 #include "server.h"
17 #include "misc.h"
18 #include "mgmt/share_config.h"
19
20 static const struct smb_sid domain = {1, 4, {0, 0, 0, 0, 0, 5},
21 {cpu_to_le32(21), cpu_to_le32(1), cpu_to_le32(2), cpu_to_le32(3),
22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
23
24 /* security id for everyone/world system group */
25 static const struct smb_sid creator_owner = {
26 1, 1, {0, 0, 0, 0, 0, 3}, {0} };
27 /* security id for everyone/world system group */
28 static const struct smb_sid creator_group = {
29 1, 1, {0, 0, 0, 0, 0, 3}, {cpu_to_le32(1)} };
30
31 /* security id for everyone/world system group */
32 static const struct smb_sid sid_everyone = {
33 1, 1, {0, 0, 0, 0, 0, 1}, {0} };
34 /* security id for Authenticated Users system group */
35 static const struct smb_sid sid_authusers = {
36 1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11)} };
37
38 /* S-1-22-1 Unmapped Unix users */
39 static const struct smb_sid sid_unix_users = {1, 1, {0, 0, 0, 0, 0, 22},
40 {cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
41
42 /* S-1-22-2 Unmapped Unix groups */
43 static const struct smb_sid sid_unix_groups = { 1, 1, {0, 0, 0, 0, 0, 22},
44 {cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
45
46 /*
47 * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
48 */
49
50 /* S-1-5-88 MS NFS and Apple style UID/GID/mode */
51
52 /* S-1-5-88-1 Unix uid */
53 static const struct smb_sid sid_unix_NFS_users = { 1, 2, {0, 0, 0, 0, 0, 5},
54 {cpu_to_le32(88),
55 cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
56
57 /* S-1-5-88-2 Unix gid */
58 static const struct smb_sid sid_unix_NFS_groups = { 1, 2, {0, 0, 0, 0, 0, 5},
59 {cpu_to_le32(88),
60 cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
61
62 /* S-1-5-88-3 Unix mode */
63 static const struct smb_sid sid_unix_NFS_mode = { 1, 2, {0, 0, 0, 0, 0, 5},
64 {cpu_to_le32(88),
65 cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
66
67 /*
68 * if the two SIDs (roughly equivalent to a UUID for a user or group) are
69 * the same returns zero, if they do not match returns non-zero.
70 */
compare_sids(const struct smb_sid * ctsid,const struct smb_sid * cwsid)71 int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid)
72 {
73 int i;
74 int num_subauth, num_sat, num_saw;
75
76 if (!ctsid || !cwsid)
77 return 1;
78
79 /* compare the revision */
80 if (ctsid->revision != cwsid->revision) {
81 if (ctsid->revision > cwsid->revision)
82 return 1;
83 else
84 return -1;
85 }
86
87 /* compare all of the six auth values */
88 for (i = 0; i < NUM_AUTHS; ++i) {
89 if (ctsid->authority[i] != cwsid->authority[i]) {
90 if (ctsid->authority[i] > cwsid->authority[i])
91 return 1;
92 else
93 return -1;
94 }
95 }
96
97 /* compare all of the subauth values if any */
98 num_sat = ctsid->num_subauth;
99 num_saw = cwsid->num_subauth;
100 num_subauth = min(num_sat, num_saw);
101 if (num_subauth) {
102 for (i = 0; i < num_subauth; ++i) {
103 if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) {
104 if (le32_to_cpu(ctsid->sub_auth[i]) >
105 le32_to_cpu(cwsid->sub_auth[i]))
106 return 1;
107 else
108 return -1;
109 }
110 }
111 }
112
113 return 0; /* sids compare/match */
114 }
115
smb_copy_sid(struct smb_sid * dst,const struct smb_sid * src)116 static void smb_copy_sid(struct smb_sid *dst, const struct smb_sid *src)
117 {
118 int i;
119
120 dst->revision = src->revision;
121 dst->num_subauth = min_t(u8, src->num_subauth, SID_MAX_SUB_AUTHORITIES);
122 for (i = 0; i < NUM_AUTHS; ++i)
123 dst->authority[i] = src->authority[i];
124 for (i = 0; i < dst->num_subauth; ++i)
125 dst->sub_auth[i] = src->sub_auth[i];
126 }
127
128 /*
129 * change posix mode to reflect permissions
130 * pmode is the existing mode (we only want to overwrite part of this
131 * bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007
132 */
access_flags_to_mode(struct smb_fattr * fattr,__le32 ace_flags,int type)133 static umode_t access_flags_to_mode(struct smb_fattr *fattr, __le32 ace_flags,
134 int type)
135 {
136 __u32 flags = le32_to_cpu(ace_flags);
137 umode_t mode = 0;
138
139 if (flags & GENERIC_ALL) {
140 mode = 0777;
141 ksmbd_debug(SMB, "all perms\n");
142 return mode;
143 }
144
145 if ((flags & GENERIC_READ) || (flags & FILE_READ_RIGHTS))
146 mode = 0444;
147 if ((flags & GENERIC_WRITE) || (flags & FILE_WRITE_RIGHTS)) {
148 mode |= 0222;
149 if (S_ISDIR(fattr->cf_mode))
150 mode |= 0111;
151 }
152 if ((flags & GENERIC_EXECUTE) || (flags & FILE_EXEC_RIGHTS))
153 mode |= 0111;
154
155 if (type == ACCESS_DENIED_ACE_TYPE || type == ACCESS_DENIED_OBJECT_ACE_TYPE)
156 mode = ~mode;
157
158 ksmbd_debug(SMB, "access flags 0x%x mode now %04o\n", flags, mode);
159
160 return mode;
161 }
162
163 /*
164 * Generate access flags to reflect permissions mode is the existing mode.
165 * This function is called for every ACE in the DACL whose SID matches
166 * with either owner or group or everyone.
167 */
mode_to_access_flags(umode_t mode,umode_t bits_to_use,__u32 * pace_flags)168 static void mode_to_access_flags(umode_t mode, umode_t bits_to_use,
169 __u32 *pace_flags)
170 {
171 /* reset access mask */
172 *pace_flags = 0x0;
173
174 /* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */
175 mode &= bits_to_use;
176
177 /*
178 * check for R/W/X UGO since we do not know whose flags
179 * is this but we have cleared all the bits sans RWX for
180 * either user or group or other as per bits_to_use
181 */
182 if (mode & 0444)
183 *pace_flags |= SET_FILE_READ_RIGHTS;
184 if (mode & 0222)
185 *pace_flags |= FILE_WRITE_RIGHTS;
186 if (mode & 0111)
187 *pace_flags |= SET_FILE_EXEC_RIGHTS;
188
189 ksmbd_debug(SMB, "mode: %o, access flags now 0x%x\n",
190 mode, *pace_flags);
191 }
192
fill_ace_for_sid(struct smb_ace * pntace,const struct smb_sid * psid,int type,int flags,umode_t mode,umode_t bits)193 static __u16 fill_ace_for_sid(struct smb_ace *pntace,
194 const struct smb_sid *psid, int type, int flags,
195 umode_t mode, umode_t bits)
196 {
197 int i;
198 __u16 size = 0;
199 __u32 access_req = 0;
200
201 pntace->type = type;
202 pntace->flags = flags;
203 mode_to_access_flags(mode, bits, &access_req);
204 if (!access_req)
205 access_req = SET_MINIMUM_RIGHTS;
206 pntace->access_req = cpu_to_le32(access_req);
207
208 pntace->sid.revision = psid->revision;
209 pntace->sid.num_subauth = psid->num_subauth;
210 for (i = 0; i < NUM_AUTHS; i++)
211 pntace->sid.authority[i] = psid->authority[i];
212 for (i = 0; i < psid->num_subauth; i++)
213 pntace->sid.sub_auth[i] = psid->sub_auth[i];
214
215 size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4);
216 pntace->size = cpu_to_le16(size);
217
218 return size;
219 }
220
id_to_sid(unsigned int cid,uint sidtype,struct smb_sid * ssid)221 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid)
222 {
223 switch (sidtype) {
224 case SIDOWNER:
225 smb_copy_sid(ssid, &server_conf.domain_sid);
226 break;
227 case SIDUNIX_USER:
228 smb_copy_sid(ssid, &sid_unix_users);
229 break;
230 case SIDUNIX_GROUP:
231 smb_copy_sid(ssid, &sid_unix_groups);
232 break;
233 case SIDCREATOR_OWNER:
234 smb_copy_sid(ssid, &creator_owner);
235 return;
236 case SIDCREATOR_GROUP:
237 smb_copy_sid(ssid, &creator_group);
238 return;
239 case SIDNFS_USER:
240 smb_copy_sid(ssid, &sid_unix_NFS_users);
241 break;
242 case SIDNFS_GROUP:
243 smb_copy_sid(ssid, &sid_unix_NFS_groups);
244 break;
245 case SIDNFS_MODE:
246 smb_copy_sid(ssid, &sid_unix_NFS_mode);
247 break;
248 default:
249 return;
250 }
251
252 /* RID */
253 ssid->sub_auth[ssid->num_subauth] = cpu_to_le32(cid);
254 ssid->num_subauth++;
255 }
256
sid_to_id(struct mnt_idmap * idmap,struct smb_sid * psid,uint sidtype,struct smb_fattr * fattr)257 static int sid_to_id(struct mnt_idmap *idmap,
258 struct smb_sid *psid, uint sidtype,
259 struct smb_fattr *fattr)
260 {
261 int rc = -EINVAL;
262
263 /*
264 * If we have too many subauthorities, then something is really wrong.
265 * Just return an error.
266 */
267 if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) {
268 pr_err("%s: %u subauthorities is too many!\n",
269 __func__, psid->num_subauth);
270 return -EIO;
271 }
272
273 if (psid->num_subauth == 0) {
274 pr_err("%s: zero subauthorities!\n", __func__);
275 return -EIO;
276 }
277
278 if (sidtype == SIDOWNER) {
279 kuid_t uid;
280 uid_t id;
281
282 id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
283 uid = KUIDT_INIT(id);
284 uid = from_vfsuid(idmap, &init_user_ns, VFSUIDT_INIT(uid));
285 if (uid_valid(uid)) {
286 fattr->cf_uid = uid;
287 rc = 0;
288 }
289 } else {
290 kgid_t gid;
291 gid_t id;
292
293 id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
294 gid = KGIDT_INIT(id);
295 gid = from_vfsgid(idmap, &init_user_ns, VFSGIDT_INIT(gid));
296 if (gid_valid(gid)) {
297 fattr->cf_gid = gid;
298 rc = 0;
299 }
300 }
301
302 return rc;
303 }
304
posix_state_to_acl(struct posix_acl_state * state,struct posix_acl_entry * pace)305 void posix_state_to_acl(struct posix_acl_state *state,
306 struct posix_acl_entry *pace)
307 {
308 int i;
309
310 pace->e_tag = ACL_USER_OBJ;
311 pace->e_perm = state->owner.allow;
312 for (i = 0; i < state->users->n; i++) {
313 pace++;
314 pace->e_tag = ACL_USER;
315 pace->e_uid = state->users->aces[i].uid;
316 pace->e_perm = state->users->aces[i].perms.allow;
317 }
318
319 pace++;
320 pace->e_tag = ACL_GROUP_OBJ;
321 pace->e_perm = state->group.allow;
322
323 for (i = 0; i < state->groups->n; i++) {
324 pace++;
325 pace->e_tag = ACL_GROUP;
326 pace->e_gid = state->groups->aces[i].gid;
327 pace->e_perm = state->groups->aces[i].perms.allow;
328 }
329
330 if (state->users->n || state->groups->n) {
331 pace++;
332 pace->e_tag = ACL_MASK;
333 pace->e_perm = state->mask.allow;
334 }
335
336 pace++;
337 pace->e_tag = ACL_OTHER;
338 pace->e_perm = state->other.allow;
339 }
340
init_acl_state(struct posix_acl_state * state,u16 cnt)341 int init_acl_state(struct posix_acl_state *state, u16 cnt)
342 {
343 int alloc;
344
345 memset(state, 0, sizeof(struct posix_acl_state));
346 /*
347 * In the worst case, each individual acl could be for a distinct
348 * named user or group, but we don't know which, so we allocate
349 * enough space for either:
350 */
351 alloc = sizeof(struct posix_ace_state_array)
352 + cnt * sizeof(struct posix_user_ace_state);
353 state->users = kzalloc(alloc, KSMBD_DEFAULT_GFP);
354 if (!state->users)
355 return -ENOMEM;
356 state->groups = kzalloc(alloc, KSMBD_DEFAULT_GFP);
357 if (!state->groups) {
358 kfree(state->users);
359 return -ENOMEM;
360 }
361 return 0;
362 }
363
free_acl_state(struct posix_acl_state * state)364 void free_acl_state(struct posix_acl_state *state)
365 {
366 kfree(state->users);
367 kfree(state->groups);
368 }
369
parse_dacl(struct mnt_idmap * idmap,struct smb_acl * pdacl,char * end_of_acl,struct smb_sid * pownersid,struct smb_sid * pgrpsid,struct smb_fattr * fattr)370 static void parse_dacl(struct mnt_idmap *idmap,
371 struct smb_acl *pdacl, char *end_of_acl,
372 struct smb_sid *pownersid, struct smb_sid *pgrpsid,
373 struct smb_fattr *fattr)
374 {
375 int i, ret;
376 u16 num_aces = 0;
377 unsigned int acl_size;
378 char *acl_base;
379 struct smb_ace **ppace;
380 struct posix_acl_entry *cf_pace, *cf_pdace;
381 struct posix_acl_state acl_state, default_acl_state;
382 umode_t mode = 0, acl_mode;
383 bool owner_found = false, group_found = false, others_found = false;
384
385 if (!pdacl)
386 return;
387
388 /* validate that we do not go past end of acl */
389 if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) ||
390 end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
391 pr_err("ACL too small to parse DACL\n");
392 return;
393 }
394
395 ksmbd_debug(SMB, "DACL revision %d size %d num aces %d\n",
396 le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
397 le16_to_cpu(pdacl->num_aces));
398
399 acl_base = (char *)pdacl;
400 acl_size = sizeof(struct smb_acl);
401
402 num_aces = le16_to_cpu(pdacl->num_aces);
403 if (num_aces <= 0)
404 return;
405
406 if (num_aces > (le16_to_cpu(pdacl->size) - sizeof(struct smb_acl)) /
407 (offsetof(struct smb_ace, sid) +
408 offsetof(struct smb_sid, sub_auth) + sizeof(__le16)))
409 return;
410
411 ret = init_acl_state(&acl_state, num_aces);
412 if (ret)
413 return;
414 ret = init_acl_state(&default_acl_state, num_aces);
415 if (ret) {
416 free_acl_state(&acl_state);
417 return;
418 }
419
420 ppace = kmalloc_objs(struct smb_ace *, num_aces, KSMBD_DEFAULT_GFP);
421 if (!ppace) {
422 free_acl_state(&default_acl_state);
423 free_acl_state(&acl_state);
424 return;
425 }
426
427 /*
428 * reset rwx permissions for user/group/other.
429 * Also, if num_aces is 0 i.e. DACL has no ACEs,
430 * user/group/other have no permissions
431 */
432 for (i = 0; i < num_aces; ++i) {
433 if (end_of_acl - acl_base < acl_size)
434 break;
435
436 ppace[i] = (struct smb_ace *)(acl_base + acl_size);
437 acl_base = (char *)ppace[i];
438 acl_size = offsetof(struct smb_ace, sid) +
439 offsetof(struct smb_sid, sub_auth);
440
441 if (end_of_acl - acl_base < acl_size ||
442 ppace[i]->sid.num_subauth == 0 ||
443 ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
444 (end_of_acl - acl_base <
445 acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) ||
446 (le16_to_cpu(ppace[i]->size) <
447 acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth))
448 break;
449
450 acl_size = le16_to_cpu(ppace[i]->size);
451 ppace[i]->access_req =
452 smb_map_generic_desired_access(ppace[i]->access_req);
453
454 if (!(compare_sids(&ppace[i]->sid, &sid_unix_NFS_mode))) {
455 fattr->cf_mode =
456 le32_to_cpu(ppace[i]->sid.sub_auth[2]);
457 break;
458 } else if (!compare_sids(&ppace[i]->sid, pownersid)) {
459 acl_mode = access_flags_to_mode(fattr,
460 ppace[i]->access_req,
461 ppace[i]->type);
462 acl_mode &= 0700;
463
464 if (!owner_found) {
465 mode &= ~(0700);
466 mode |= acl_mode;
467 }
468 owner_found = true;
469 } else if (!compare_sids(&ppace[i]->sid, pgrpsid) ||
470 ppace[i]->sid.sub_auth[ppace[i]->sid.num_subauth - 1] ==
471 DOMAIN_USER_RID_LE) {
472 acl_mode = access_flags_to_mode(fattr,
473 ppace[i]->access_req,
474 ppace[i]->type);
475 acl_mode &= 0070;
476 if (!group_found) {
477 mode &= ~(0070);
478 mode |= acl_mode;
479 }
480 group_found = true;
481 } else if (!compare_sids(&ppace[i]->sid, &sid_everyone)) {
482 acl_mode = access_flags_to_mode(fattr,
483 ppace[i]->access_req,
484 ppace[i]->type);
485 acl_mode &= 0007;
486 if (!others_found) {
487 mode &= ~(0007);
488 mode |= acl_mode;
489 }
490 others_found = true;
491 } else if (!compare_sids(&ppace[i]->sid, &creator_owner)) {
492 continue;
493 } else if (!compare_sids(&ppace[i]->sid, &creator_group)) {
494 continue;
495 } else if (!compare_sids(&ppace[i]->sid, &sid_authusers)) {
496 continue;
497 } else {
498 struct smb_fattr temp_fattr;
499
500 acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req,
501 ppace[i]->type);
502 temp_fattr.cf_uid = INVALID_UID;
503 ret = sid_to_id(idmap, &ppace[i]->sid, SIDOWNER, &temp_fattr);
504 if (ret || uid_eq(temp_fattr.cf_uid, INVALID_UID)) {
505 pr_err("%s: Error %d mapping Owner SID to uid\n",
506 __func__, ret);
507 continue;
508 }
509
510 acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004;
511 acl_state.users->aces[acl_state.users->n].uid =
512 temp_fattr.cf_uid;
513 acl_state.users->aces[acl_state.users->n++].perms.allow =
514 ((acl_mode & 0700) >> 6) | 0004;
515 default_acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004;
516 default_acl_state.users->aces[default_acl_state.users->n].uid =
517 temp_fattr.cf_uid;
518 default_acl_state.users->aces[default_acl_state.users->n++].perms.allow =
519 ((acl_mode & 0700) >> 6) | 0004;
520 }
521 }
522 kfree(ppace);
523
524 if (owner_found) {
525 /* The owner must be set to at least read-only. */
526 acl_state.owner.allow = ((mode & 0700) >> 6) | 0004;
527 acl_state.users->aces[acl_state.users->n].uid = fattr->cf_uid;
528 acl_state.users->aces[acl_state.users->n++].perms.allow =
529 ((mode & 0700) >> 6) | 0004;
530 default_acl_state.owner.allow = ((mode & 0700) >> 6) | 0004;
531 default_acl_state.users->aces[default_acl_state.users->n].uid =
532 fattr->cf_uid;
533 default_acl_state.users->aces[default_acl_state.users->n++].perms.allow =
534 ((mode & 0700) >> 6) | 0004;
535 }
536
537 if (group_found) {
538 acl_state.group.allow = (mode & 0070) >> 3;
539 acl_state.groups->aces[acl_state.groups->n].gid =
540 fattr->cf_gid;
541 acl_state.groups->aces[acl_state.groups->n++].perms.allow =
542 (mode & 0070) >> 3;
543 default_acl_state.group.allow = (mode & 0070) >> 3;
544 default_acl_state.groups->aces[default_acl_state.groups->n].gid =
545 fattr->cf_gid;
546 default_acl_state.groups->aces[default_acl_state.groups->n++].perms.allow =
547 (mode & 0070) >> 3;
548 }
549
550 if (others_found) {
551 fattr->cf_mode &= ~(0007);
552 fattr->cf_mode |= mode & 0007;
553
554 acl_state.other.allow = mode & 0007;
555 default_acl_state.other.allow = mode & 0007;
556 }
557
558 if (acl_state.users->n || acl_state.groups->n) {
559 acl_state.mask.allow = 0x07;
560
561 if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
562 fattr->cf_acls =
563 posix_acl_alloc(acl_state.users->n +
564 acl_state.groups->n + 4, KSMBD_DEFAULT_GFP);
565 if (fattr->cf_acls) {
566 cf_pace = fattr->cf_acls->a_entries;
567 posix_state_to_acl(&acl_state, cf_pace);
568 }
569 }
570 }
571
572 if (default_acl_state.users->n || default_acl_state.groups->n) {
573 default_acl_state.mask.allow = 0x07;
574
575 if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
576 fattr->cf_dacls =
577 posix_acl_alloc(default_acl_state.users->n +
578 default_acl_state.groups->n + 4, KSMBD_DEFAULT_GFP);
579 if (fattr->cf_dacls) {
580 cf_pdace = fattr->cf_dacls->a_entries;
581 posix_state_to_acl(&default_acl_state, cf_pdace);
582 }
583 }
584 }
585 free_acl_state(&acl_state);
586 free_acl_state(&default_acl_state);
587 }
588
set_posix_acl_entries_dacl(struct mnt_idmap * idmap,struct smb_ace * pndace,struct smb_fattr * fattr,u16 * num_aces,u16 * size,u32 nt_aces_num)589 static void set_posix_acl_entries_dacl(struct mnt_idmap *idmap,
590 struct smb_ace *pndace,
591 struct smb_fattr *fattr, u16 *num_aces,
592 u16 *size, u32 nt_aces_num)
593 {
594 struct posix_acl_entry *pace;
595 struct smb_sid *sid;
596 struct smb_ace *ntace;
597 int i, j;
598
599 if (!fattr->cf_acls)
600 goto posix_default_acl;
601
602 pace = fattr->cf_acls->a_entries;
603 for (i = 0; i < fattr->cf_acls->a_count; i++, pace++) {
604 int flags = 0;
605
606 sid = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
607 if (!sid)
608 break;
609
610 if (pace->e_tag == ACL_USER) {
611 uid_t uid;
612 unsigned int sid_type = SIDOWNER;
613
614 uid = posix_acl_uid_translate(idmap, pace);
615 if (!uid)
616 sid_type = SIDUNIX_USER;
617 id_to_sid(uid, sid_type, sid);
618 } else if (pace->e_tag == ACL_GROUP) {
619 gid_t gid;
620
621 gid = posix_acl_gid_translate(idmap, pace);
622 id_to_sid(gid, SIDUNIX_GROUP, sid);
623 } else if (pace->e_tag == ACL_OTHER && !nt_aces_num) {
624 smb_copy_sid(sid, &sid_everyone);
625 } else {
626 kfree(sid);
627 continue;
628 }
629 ntace = pndace;
630 for (j = 0; j < nt_aces_num; j++) {
631 if (ntace->sid.sub_auth[ntace->sid.num_subauth - 1] ==
632 sid->sub_auth[sid->num_subauth - 1])
633 goto pass_same_sid;
634 ntace = (struct smb_ace *)((char *)ntace +
635 le16_to_cpu(ntace->size));
636 }
637
638 if (S_ISDIR(fattr->cf_mode) && pace->e_tag == ACL_OTHER)
639 flags = 0x03;
640
641 ntace = (struct smb_ace *)((char *)pndace + *size);
642 *size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, flags,
643 pace->e_perm, 0777);
644 (*num_aces)++;
645 if (pace->e_tag == ACL_USER)
646 ntace->access_req |=
647 FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
648
649 if (S_ISDIR(fattr->cf_mode) &&
650 (pace->e_tag == ACL_USER || pace->e_tag == ACL_GROUP)) {
651 ntace = (struct smb_ace *)((char *)pndace + *size);
652 *size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED,
653 0x03, pace->e_perm, 0777);
654 (*num_aces)++;
655 if (pace->e_tag == ACL_USER)
656 ntace->access_req |=
657 FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
658 }
659
660 pass_same_sid:
661 kfree(sid);
662 }
663
664 if (nt_aces_num)
665 return;
666
667 posix_default_acl:
668 if (!fattr->cf_dacls)
669 return;
670
671 pace = fattr->cf_dacls->a_entries;
672 for (i = 0; i < fattr->cf_dacls->a_count; i++, pace++) {
673 sid = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
674 if (!sid)
675 break;
676
677 if (pace->e_tag == ACL_USER) {
678 uid_t uid;
679
680 uid = posix_acl_uid_translate(idmap, pace);
681 id_to_sid(uid, SIDCREATOR_OWNER, sid);
682 } else if (pace->e_tag == ACL_GROUP) {
683 gid_t gid;
684
685 gid = posix_acl_gid_translate(idmap, pace);
686 id_to_sid(gid, SIDCREATOR_GROUP, sid);
687 } else {
688 kfree(sid);
689 continue;
690 }
691
692 ntace = (struct smb_ace *)((char *)pndace + *size);
693 *size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 0x0b,
694 pace->e_perm, 0777);
695 (*num_aces)++;
696 if (pace->e_tag == ACL_USER)
697 ntace->access_req |=
698 FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
699 kfree(sid);
700 }
701 }
702
set_ntacl_dacl(struct mnt_idmap * idmap,struct smb_acl * pndacl,struct smb_acl * nt_dacl,unsigned int aces_size,const struct smb_sid * pownersid,const struct smb_sid * pgrpsid,struct smb_fattr * fattr)703 static void set_ntacl_dacl(struct mnt_idmap *idmap,
704 struct smb_acl *pndacl,
705 struct smb_acl *nt_dacl,
706 unsigned int aces_size,
707 const struct smb_sid *pownersid,
708 const struct smb_sid *pgrpsid,
709 struct smb_fattr *fattr)
710 {
711 struct smb_ace *ntace, *pndace;
712 u16 nt_num_aces = le16_to_cpu(nt_dacl->num_aces), num_aces = 0;
713 unsigned short size = 0;
714 int i;
715
716 pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
717 if (nt_num_aces) {
718 ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl));
719 for (i = 0; i < nt_num_aces; i++) {
720 unsigned short nt_ace_size;
721
722 if (offsetof(struct smb_ace, access_req) > aces_size)
723 break;
724
725 nt_ace_size = le16_to_cpu(ntace->size);
726 if (nt_ace_size > aces_size)
727 break;
728
729 memcpy((char *)pndace + size, ntace, nt_ace_size);
730 size += nt_ace_size;
731 aces_size -= nt_ace_size;
732 ntace = (struct smb_ace *)((char *)ntace + nt_ace_size);
733 num_aces++;
734 }
735 }
736
737 set_posix_acl_entries_dacl(idmap, pndace, fattr,
738 &num_aces, &size, nt_num_aces);
739 pndacl->num_aces = cpu_to_le16(num_aces);
740 pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
741 }
742
set_mode_dacl(struct mnt_idmap * idmap,struct smb_acl * pndacl,struct smb_fattr * fattr)743 static void set_mode_dacl(struct mnt_idmap *idmap,
744 struct smb_acl *pndacl, struct smb_fattr *fattr)
745 {
746 struct smb_ace *pace, *pndace;
747 u16 num_aces = 0;
748 u16 size = 0, ace_size = 0;
749 uid_t uid;
750 const struct smb_sid *sid;
751
752 pace = pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
753
754 if (fattr->cf_acls) {
755 set_posix_acl_entries_dacl(idmap, pndace, fattr,
756 &num_aces, &size, num_aces);
757 goto out;
758 }
759
760 /* owner RID */
761 uid = from_kuid(&init_user_ns, fattr->cf_uid);
762 if (uid)
763 sid = &server_conf.domain_sid;
764 else
765 sid = &sid_unix_users;
766 ace_size = fill_ace_for_sid(pace, sid, ACCESS_ALLOWED, 0,
767 fattr->cf_mode, 0700);
768 pace->sid.sub_auth[pace->sid.num_subauth++] = cpu_to_le32(uid);
769 pace->size = cpu_to_le16(ace_size + 4);
770 size += le16_to_cpu(pace->size);
771 pace = (struct smb_ace *)((char *)pndace + size);
772
773 /* Group RID */
774 ace_size = fill_ace_for_sid(pace, &sid_unix_groups,
775 ACCESS_ALLOWED, 0, fattr->cf_mode, 0070);
776 pace->sid.sub_auth[pace->sid.num_subauth++] =
777 cpu_to_le32(from_kgid(&init_user_ns, fattr->cf_gid));
778 pace->size = cpu_to_le16(ace_size + 4);
779 size += le16_to_cpu(pace->size);
780 pace = (struct smb_ace *)((char *)pndace + size);
781 num_aces = 3;
782
783 if (S_ISDIR(fattr->cf_mode)) {
784 pace = (struct smb_ace *)((char *)pndace + size);
785
786 /* creator owner */
787 size += fill_ace_for_sid(pace, &creator_owner, ACCESS_ALLOWED,
788 0x0b, fattr->cf_mode, 0700);
789 pace = (struct smb_ace *)((char *)pndace + size);
790
791 /* creator group */
792 size += fill_ace_for_sid(pace, &creator_group, ACCESS_ALLOWED,
793 0x0b, fattr->cf_mode, 0070);
794 pace = (struct smb_ace *)((char *)pndace + size);
795 num_aces = 5;
796 }
797
798 /* other */
799 size += fill_ace_for_sid(pace, &sid_everyone, ACCESS_ALLOWED, 0,
800 fattr->cf_mode, 0007);
801
802 out:
803 pndacl->num_aces = cpu_to_le16(num_aces);
804 pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
805 }
806
parse_sid(struct smb_sid * psid,char * end_of_acl)807 static int parse_sid(struct smb_sid *psid, char *end_of_acl)
808 {
809 /*
810 * validate that we do not go past end of ACL - sid must be at least 8
811 * bytes long (assuming no sub-auths - e.g. the null SID
812 */
813 if (end_of_acl < (char *)psid + 8) {
814 pr_err("ACL too small to parse SID %p\n", psid);
815 return -EINVAL;
816 }
817
818 if (!psid->num_subauth)
819 return 0;
820
821 if (psid->num_subauth > SID_MAX_SUB_AUTHORITIES ||
822 end_of_acl < (char *)psid + 8 + sizeof(__le32) * psid->num_subauth)
823 return -EINVAL;
824
825 return 0;
826 }
827
828 /* Convert CIFS ACL to POSIX form */
parse_sec_desc(struct mnt_idmap * idmap,struct smb_ntsd * pntsd,int acl_len,struct smb_fattr * fattr)829 int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
830 int acl_len, struct smb_fattr *fattr)
831 {
832 int rc = 0;
833 struct smb_sid *owner_sid_ptr, *group_sid_ptr;
834 struct smb_acl *dacl_ptr; /* no need for SACL ptr */
835 char *end_of_acl = ((char *)pntsd) + acl_len;
836 __u32 dacloffset;
837 int pntsd_type;
838
839 if (!pntsd)
840 return -EIO;
841
842 if (acl_len < sizeof(struct smb_ntsd))
843 return -EINVAL;
844
845 owner_sid_ptr = (struct smb_sid *)((char *)pntsd +
846 le32_to_cpu(pntsd->osidoffset));
847 group_sid_ptr = (struct smb_sid *)((char *)pntsd +
848 le32_to_cpu(pntsd->gsidoffset));
849 dacloffset = le32_to_cpu(pntsd->dacloffset);
850 dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset);
851 ksmbd_debug(SMB,
852 "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n",
853 pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
854 le32_to_cpu(pntsd->gsidoffset),
855 le32_to_cpu(pntsd->sacloffset), dacloffset);
856
857 pntsd_type = le16_to_cpu(pntsd->type);
858 if (!(pntsd_type & DACL_PRESENT)) {
859 ksmbd_debug(SMB, "DACL_PRESENT in DACL type is not set\n");
860 return rc;
861 }
862
863 pntsd->type = cpu_to_le16(DACL_PRESENT);
864
865 if (pntsd->osidoffset) {
866 if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd))
867 return -EINVAL;
868
869 rc = parse_sid(owner_sid_ptr, end_of_acl);
870 if (rc) {
871 pr_err("%s: Error %d parsing Owner SID\n", __func__, rc);
872 return rc;
873 }
874
875 rc = sid_to_id(idmap, owner_sid_ptr, SIDOWNER, fattr);
876 if (rc) {
877 pr_err("%s: Error %d mapping Owner SID to uid\n",
878 __func__, rc);
879 owner_sid_ptr = NULL;
880 }
881 }
882
883 if (pntsd->gsidoffset) {
884 if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd))
885 return -EINVAL;
886
887 rc = parse_sid(group_sid_ptr, end_of_acl);
888 if (rc) {
889 pr_err("%s: Error %d mapping Owner SID to gid\n",
890 __func__, rc);
891 return rc;
892 }
893 rc = sid_to_id(idmap, group_sid_ptr, SIDUNIX_GROUP, fattr);
894 if (rc) {
895 pr_err("%s: Error %d mapping Group SID to gid\n",
896 __func__, rc);
897 group_sid_ptr = NULL;
898 }
899 }
900
901 if ((pntsd_type & (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) ==
902 (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ))
903 pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED);
904 if (pntsd_type & DACL_PROTECTED)
905 pntsd->type |= cpu_to_le16(DACL_PROTECTED);
906
907 if (dacloffset) {
908 if (dacloffset < sizeof(struct smb_ntsd))
909 return -EINVAL;
910
911 parse_dacl(idmap, dacl_ptr, end_of_acl,
912 owner_sid_ptr, group_sid_ptr, fattr);
913 }
914
915 return 0;
916 }
917
smb_acl_sec_desc_scratch_len(struct smb_fattr * fattr,struct smb_ntsd * ppntsd,int ppntsd_size,int addition_info)918 size_t smb_acl_sec_desc_scratch_len(struct smb_fattr *fattr,
919 struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info)
920 {
921 size_t len = sizeof(struct smb_ntsd);
922 size_t tmp;
923
924 if (addition_info & OWNER_SECINFO)
925 len += sizeof(struct smb_sid);
926 if (addition_info & GROUP_SECINFO)
927 len += sizeof(struct smb_sid);
928 if (!(addition_info & DACL_SECINFO))
929 return len;
930
931 len += sizeof(struct smb_acl);
932 if (ppntsd && ppntsd_size > 0) {
933 unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
934
935 if (dacl_offset < ppntsd_size &&
936 check_add_overflow(len, ppntsd_size - dacl_offset, &len))
937 return 0;
938 }
939
940 if (fattr->cf_acls) {
941 if (check_mul_overflow((size_t)fattr->cf_acls->a_count,
942 2 * sizeof(struct smb_ace), &tmp) ||
943 check_add_overflow(len, tmp, &len))
944 return 0;
945 } else {
946 /* default/minimum DACL */
947 if (check_add_overflow(len, 5 * sizeof(struct smb_ace), &len))
948 return 0;
949 }
950
951 if (fattr->cf_dacls) {
952 if (check_mul_overflow((size_t)fattr->cf_dacls->a_count,
953 sizeof(struct smb_ace), &tmp) ||
954 check_add_overflow(len, tmp, &len))
955 return 0;
956 }
957
958 return len;
959 }
960
961 /* Convert permission bits from mode to equivalent CIFS ACL */
build_sec_desc(struct mnt_idmap * idmap,struct smb_ntsd * pntsd,struct smb_ntsd * ppntsd,int ppntsd_size,int addition_info,__u32 * secdesclen,struct smb_fattr * fattr)962 int build_sec_desc(struct mnt_idmap *idmap,
963 struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd,
964 int ppntsd_size, int addition_info, __u32 *secdesclen,
965 struct smb_fattr *fattr)
966 {
967 int rc = 0;
968 __u32 offset;
969 struct smb_sid *owner_sid_ptr, *group_sid_ptr;
970 struct smb_sid *nowner_sid_ptr, *ngroup_sid_ptr;
971 struct smb_acl *dacl_ptr = NULL; /* no need for SACL ptr */
972 uid_t uid;
973 gid_t gid;
974 unsigned int sid_type = SIDOWNER;
975
976 nowner_sid_ptr = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
977 if (!nowner_sid_ptr)
978 return -ENOMEM;
979
980 uid = from_kuid(&init_user_ns, fattr->cf_uid);
981 if (!uid)
982 sid_type = SIDUNIX_USER;
983 id_to_sid(uid, sid_type, nowner_sid_ptr);
984
985 ngroup_sid_ptr = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
986 if (!ngroup_sid_ptr) {
987 kfree(nowner_sid_ptr);
988 return -ENOMEM;
989 }
990
991 gid = from_kgid(&init_user_ns, fattr->cf_gid);
992 id_to_sid(gid, SIDUNIX_GROUP, ngroup_sid_ptr);
993
994 offset = sizeof(struct smb_ntsd);
995 pntsd->sacloffset = 0;
996 pntsd->revision = cpu_to_le16(1);
997 pntsd->type = cpu_to_le16(SELF_RELATIVE);
998 if (ppntsd)
999 pntsd->type |= ppntsd->type;
1000
1001 if (addition_info & OWNER_SECINFO) {
1002 pntsd->osidoffset = cpu_to_le32(offset);
1003 owner_sid_ptr = (struct smb_sid *)((char *)pntsd + offset);
1004 smb_copy_sid(owner_sid_ptr, nowner_sid_ptr);
1005 offset += 1 + 1 + 6 + (nowner_sid_ptr->num_subauth * 4);
1006 }
1007
1008 if (addition_info & GROUP_SECINFO) {
1009 pntsd->gsidoffset = cpu_to_le32(offset);
1010 group_sid_ptr = (struct smb_sid *)((char *)pntsd + offset);
1011 smb_copy_sid(group_sid_ptr, ngroup_sid_ptr);
1012 offset += 1 + 1 + 6 + (ngroup_sid_ptr->num_subauth * 4);
1013 }
1014
1015 if (addition_info & DACL_SECINFO) {
1016 pntsd->type |= cpu_to_le16(DACL_PRESENT);
1017 dacl_ptr = (struct smb_acl *)((char *)pntsd + offset);
1018 dacl_ptr->revision = cpu_to_le16(2);
1019 dacl_ptr->size = cpu_to_le16(sizeof(struct smb_acl));
1020 dacl_ptr->num_aces = 0;
1021
1022 if (!ppntsd) {
1023 set_mode_dacl(idmap, dacl_ptr, fattr);
1024 } else {
1025 struct smb_acl *ppdacl_ptr;
1026 unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
1027 int ppdacl_size, ntacl_size = ppntsd_size - dacl_offset;
1028
1029 if (!dacl_offset ||
1030 (dacl_offset + sizeof(struct smb_acl) > ppntsd_size))
1031 goto out;
1032
1033 ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + dacl_offset);
1034 ppdacl_size = le16_to_cpu(ppdacl_ptr->size);
1035 if (ppdacl_size > ntacl_size ||
1036 ppdacl_size < sizeof(struct smb_acl))
1037 goto out;
1038
1039 set_ntacl_dacl(idmap, dacl_ptr, ppdacl_ptr,
1040 ntacl_size - sizeof(struct smb_acl),
1041 nowner_sid_ptr, ngroup_sid_ptr,
1042 fattr);
1043 }
1044 pntsd->dacloffset = cpu_to_le32(offset);
1045 offset += le16_to_cpu(dacl_ptr->size);
1046 }
1047
1048 out:
1049 kfree(nowner_sid_ptr);
1050 kfree(ngroup_sid_ptr);
1051 *secdesclen = offset;
1052 return rc;
1053 }
1054
smb_set_ace(struct smb_ace * ace,const struct smb_sid * sid,u8 type,u8 flags,__le32 access_req)1055 static void smb_set_ace(struct smb_ace *ace, const struct smb_sid *sid, u8 type,
1056 u8 flags, __le32 access_req)
1057 {
1058 ace->type = type;
1059 ace->flags = flags;
1060 ace->access_req = access_req;
1061 smb_copy_sid(&ace->sid, sid);
1062 ace->size = cpu_to_le16(1 + 1 + 2 + 4 + 1 + 1 + 6 + (sid->num_subauth * 4));
1063 }
1064
smb_inherit_dacl(struct ksmbd_conn * conn,const struct path * path,unsigned int uid,unsigned int gid)1065 int smb_inherit_dacl(struct ksmbd_conn *conn,
1066 const struct path *path,
1067 unsigned int uid, unsigned int gid)
1068 {
1069 const struct smb_sid *psid, *creator = NULL;
1070 struct smb_ace *parent_aces, *aces;
1071 struct smb_acl *parent_pdacl;
1072 struct smb_ntsd *parent_pntsd = NULL;
1073 struct smb_sid owner_sid, group_sid;
1074 struct dentry *parent = path->dentry->d_parent;
1075 struct mnt_idmap *idmap = mnt_idmap(path->mnt);
1076 int inherited_flags = 0, flags = 0, i, nt_size = 0, pdacl_size;
1077 int rc = 0, pntsd_type, pntsd_size, acl_len, aces_size;
1078 unsigned int dacloffset;
1079 size_t dacl_struct_end;
1080 u16 num_aces, ace_cnt = 0;
1081 char *aces_base;
1082 bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
1083
1084 pntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap,
1085 parent, &parent_pntsd);
1086 if (pntsd_size <= 0)
1087 return -ENOENT;
1088
1089 dacloffset = le32_to_cpu(parent_pntsd->dacloffset);
1090 if (!dacloffset ||
1091 check_add_overflow(dacloffset, sizeof(struct smb_acl), &dacl_struct_end) ||
1092 dacl_struct_end > (size_t)pntsd_size) {
1093 rc = -EINVAL;
1094 goto free_parent_pntsd;
1095 }
1096
1097 parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset);
1098 acl_len = pntsd_size - dacloffset;
1099 num_aces = le16_to_cpu(parent_pdacl->num_aces);
1100 pntsd_type = le16_to_cpu(parent_pntsd->type);
1101 pdacl_size = le16_to_cpu(parent_pdacl->size);
1102
1103 if (pdacl_size > acl_len || pdacl_size < sizeof(struct smb_acl)) {
1104 rc = -EINVAL;
1105 goto free_parent_pntsd;
1106 }
1107
1108 aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2,
1109 KSMBD_DEFAULT_GFP);
1110 if (!aces_base) {
1111 rc = -ENOMEM;
1112 goto free_parent_pntsd;
1113 }
1114
1115 aces = (struct smb_ace *)aces_base;
1116 parent_aces = (struct smb_ace *)((char *)parent_pdacl +
1117 sizeof(struct smb_acl));
1118 aces_size = acl_len - sizeof(struct smb_acl);
1119
1120 if (pntsd_type & DACL_AUTO_INHERITED)
1121 inherited_flags = INHERITED_ACE;
1122
1123 for (i = 0; i < num_aces; i++) {
1124 int pace_size;
1125
1126 if (offsetof(struct smb_ace, access_req) > aces_size)
1127 break;
1128
1129 pace_size = le16_to_cpu(parent_aces->size);
1130 if (pace_size > aces_size)
1131 break;
1132
1133 aces_size -= pace_size;
1134
1135 flags = parent_aces->flags;
1136 if (!smb_inherit_flags(flags, is_dir))
1137 goto pass;
1138 if (is_dir) {
1139 flags &= ~(INHERIT_ONLY_ACE | INHERITED_ACE);
1140 if (!(flags & CONTAINER_INHERIT_ACE))
1141 flags |= INHERIT_ONLY_ACE;
1142 if (flags & NO_PROPAGATE_INHERIT_ACE)
1143 flags = 0;
1144 } else {
1145 flags = 0;
1146 }
1147
1148 if (!compare_sids(&creator_owner, &parent_aces->sid)) {
1149 creator = &creator_owner;
1150 id_to_sid(uid, SIDOWNER, &owner_sid);
1151 psid = &owner_sid;
1152 } else if (!compare_sids(&creator_group, &parent_aces->sid)) {
1153 creator = &creator_group;
1154 id_to_sid(gid, SIDUNIX_GROUP, &group_sid);
1155 psid = &group_sid;
1156 } else {
1157 creator = NULL;
1158 psid = &parent_aces->sid;
1159 }
1160
1161 if (is_dir && creator && flags & CONTAINER_INHERIT_ACE) {
1162 smb_set_ace(aces, psid, parent_aces->type, inherited_flags,
1163 parent_aces->access_req);
1164 nt_size += le16_to_cpu(aces->size);
1165 ace_cnt++;
1166 aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size));
1167 flags |= INHERIT_ONLY_ACE;
1168 psid = creator;
1169 } else if (is_dir && !(parent_aces->flags & NO_PROPAGATE_INHERIT_ACE)) {
1170 psid = &parent_aces->sid;
1171 }
1172
1173 smb_set_ace(aces, psid, parent_aces->type, flags | inherited_flags,
1174 parent_aces->access_req);
1175 nt_size += le16_to_cpu(aces->size);
1176 aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size));
1177 ace_cnt++;
1178 pass:
1179 parent_aces = (struct smb_ace *)((char *)parent_aces + pace_size);
1180 }
1181
1182 if (nt_size > 0) {
1183 struct smb_ntsd *pntsd;
1184 struct smb_acl *pdacl;
1185 struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL;
1186 int powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size;
1187 int pntsd_alloc_size;
1188
1189 if (parent_pntsd->osidoffset) {
1190 powner_sid = (struct smb_sid *)((char *)parent_pntsd +
1191 le32_to_cpu(parent_pntsd->osidoffset));
1192 powner_sid_size = 1 + 1 + 6 + (powner_sid->num_subauth * 4);
1193 }
1194 if (parent_pntsd->gsidoffset) {
1195 pgroup_sid = (struct smb_sid *)((char *)parent_pntsd +
1196 le32_to_cpu(parent_pntsd->gsidoffset));
1197 pgroup_sid_size = 1 + 1 + 6 + (pgroup_sid->num_subauth * 4);
1198 }
1199
1200 pntsd_alloc_size = sizeof(struct smb_ntsd) + powner_sid_size +
1201 pgroup_sid_size + sizeof(struct smb_acl) + nt_size;
1202
1203 pntsd = kzalloc(pntsd_alloc_size, KSMBD_DEFAULT_GFP);
1204 if (!pntsd) {
1205 rc = -ENOMEM;
1206 goto free_aces_base;
1207 }
1208
1209 pntsd->revision = cpu_to_le16(1);
1210 pntsd->type = cpu_to_le16(SELF_RELATIVE | DACL_PRESENT);
1211 if (le16_to_cpu(parent_pntsd->type) & DACL_AUTO_INHERITED)
1212 pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED);
1213 pntsd_size = sizeof(struct smb_ntsd);
1214 pntsd->osidoffset = parent_pntsd->osidoffset;
1215 pntsd->gsidoffset = parent_pntsd->gsidoffset;
1216 pntsd->dacloffset = parent_pntsd->dacloffset;
1217
1218 if ((u64)le32_to_cpu(pntsd->osidoffset) + powner_sid_size >
1219 pntsd_alloc_size) {
1220 rc = -EINVAL;
1221 kfree(pntsd);
1222 goto free_aces_base;
1223 }
1224
1225 if ((u64)le32_to_cpu(pntsd->gsidoffset) + pgroup_sid_size >
1226 pntsd_alloc_size) {
1227 rc = -EINVAL;
1228 kfree(pntsd);
1229 goto free_aces_base;
1230 }
1231
1232 if ((u64)le32_to_cpu(pntsd->dacloffset) + sizeof(struct smb_acl) + nt_size >
1233 pntsd_alloc_size) {
1234 rc = -EINVAL;
1235 kfree(pntsd);
1236 goto free_aces_base;
1237 }
1238
1239 if (pntsd->osidoffset) {
1240 struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd +
1241 le32_to_cpu(pntsd->osidoffset));
1242 memcpy(owner_sid, powner_sid, powner_sid_size);
1243 pntsd_size += powner_sid_size;
1244 }
1245
1246 if (pntsd->gsidoffset) {
1247 struct smb_sid *group_sid = (struct smb_sid *)((char *)pntsd +
1248 le32_to_cpu(pntsd->gsidoffset));
1249 memcpy(group_sid, pgroup_sid, pgroup_sid_size);
1250 pntsd_size += pgroup_sid_size;
1251 }
1252
1253 if (pntsd->dacloffset) {
1254 struct smb_ace *pace;
1255
1256 pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
1257 pdacl->revision = cpu_to_le16(2);
1258 pdacl->size = cpu_to_le16(sizeof(struct smb_acl) + nt_size);
1259 pdacl->num_aces = cpu_to_le16(ace_cnt);
1260 pace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1261 memcpy(pace, aces_base, nt_size);
1262 pntsd_size += sizeof(struct smb_acl) + nt_size;
1263 }
1264
1265 ksmbd_vfs_set_sd_xattr(conn, idmap, path, pntsd, pntsd_size, false);
1266 kfree(pntsd);
1267 }
1268
1269 free_aces_base:
1270 kfree(aces_base);
1271 free_parent_pntsd:
1272 kfree(parent_pntsd);
1273 return rc;
1274 }
1275
smb_inherit_flags(int flags,bool is_dir)1276 bool smb_inherit_flags(int flags, bool is_dir)
1277 {
1278 if (!is_dir)
1279 return (flags & OBJECT_INHERIT_ACE) != 0;
1280
1281 if (flags & OBJECT_INHERIT_ACE && !(flags & NO_PROPAGATE_INHERIT_ACE))
1282 return true;
1283
1284 if (flags & CONTAINER_INHERIT_ACE)
1285 return true;
1286 return false;
1287 }
1288
smb_check_perm_dacl(struct ksmbd_conn * conn,const struct path * path,__le32 * pdaccess,int uid)1289 int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
1290 __le32 *pdaccess, int uid)
1291 {
1292 struct mnt_idmap *idmap = mnt_idmap(path->mnt);
1293 struct smb_ntsd *pntsd = NULL;
1294 struct smb_acl *pdacl;
1295 struct posix_acl *posix_acls;
1296 int rc = 0, pntsd_size, acl_size, aces_size, pdacl_size;
1297 unsigned int dacl_offset;
1298 size_t dacl_struct_end;
1299 struct smb_sid sid;
1300 int granted = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE);
1301 struct smb_ace *ace;
1302 int i, found = 0;
1303 unsigned int access_bits = 0;
1304 struct smb_ace *others_ace = NULL;
1305 struct posix_acl_entry *pa_entry;
1306 unsigned int sid_type = SIDOWNER;
1307 unsigned short ace_size;
1308
1309 ksmbd_debug(SMB, "check permission using windows acl\n");
1310 pntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap,
1311 path->dentry, &pntsd);
1312 if (pntsd_size <= 0 || !pntsd)
1313 goto err_out;
1314
1315 dacl_offset = le32_to_cpu(pntsd->dacloffset);
1316 if (!dacl_offset ||
1317 check_add_overflow(dacl_offset, sizeof(struct smb_acl), &dacl_struct_end) ||
1318 dacl_struct_end > (size_t)pntsd_size)
1319 goto err_out;
1320
1321 pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
1322 acl_size = pntsd_size - dacl_offset;
1323 pdacl_size = le16_to_cpu(pdacl->size);
1324
1325 if (pdacl_size > acl_size || pdacl_size < sizeof(struct smb_acl))
1326 goto err_out;
1327
1328 if (!pdacl->num_aces) {
1329 if (!(pdacl_size - sizeof(struct smb_acl)) &&
1330 *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) {
1331 rc = -EACCES;
1332 goto err_out;
1333 }
1334 goto err_out;
1335 }
1336
1337 if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) {
1338 granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES |
1339 DELETE;
1340
1341 ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1342 aces_size = acl_size - sizeof(struct smb_acl);
1343 for (i = 0; i < le16_to_cpu(pdacl->num_aces); i++) {
1344 if (offsetof(struct smb_ace, access_req) > aces_size)
1345 break;
1346 ace_size = le16_to_cpu(ace->size);
1347 if (ace_size > aces_size)
1348 break;
1349 aces_size -= ace_size;
1350 granted |= le32_to_cpu(ace->access_req);
1351 ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
1352 }
1353 }
1354
1355 if (!uid)
1356 sid_type = SIDUNIX_USER;
1357 id_to_sid(uid, sid_type, &sid);
1358
1359 ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1360 aces_size = acl_size - sizeof(struct smb_acl);
1361 for (i = 0; i < le16_to_cpu(pdacl->num_aces); i++) {
1362 if (offsetof(struct smb_ace, access_req) > aces_size)
1363 break;
1364 ace_size = le16_to_cpu(ace->size);
1365 if (ace_size > aces_size)
1366 break;
1367 aces_size -= ace_size;
1368
1369 if (!compare_sids(&sid, &ace->sid) ||
1370 !compare_sids(&sid_unix_NFS_mode, &ace->sid)) {
1371 found = 1;
1372 break;
1373 }
1374 if (!compare_sids(&sid_everyone, &ace->sid))
1375 others_ace = ace;
1376
1377 ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
1378 }
1379
1380 if (*pdaccess & FILE_MAXIMAL_ACCESS_LE && found) {
1381 granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES |
1382 DELETE;
1383
1384 granted |= le32_to_cpu(ace->access_req);
1385
1386 if (!pdacl->num_aces)
1387 granted = GENERIC_ALL_FLAGS;
1388 }
1389
1390 if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
1391 posix_acls = get_inode_acl(d_inode(path->dentry), ACL_TYPE_ACCESS);
1392 if (!IS_ERR_OR_NULL(posix_acls) && !found) {
1393 unsigned int id = -1;
1394
1395 pa_entry = posix_acls->a_entries;
1396 for (i = 0; i < posix_acls->a_count; i++, pa_entry++) {
1397 if (pa_entry->e_tag == ACL_USER)
1398 id = posix_acl_uid_translate(idmap, pa_entry);
1399 else if (pa_entry->e_tag == ACL_GROUP)
1400 id = posix_acl_gid_translate(idmap, pa_entry);
1401 else
1402 continue;
1403
1404 if (id == uid) {
1405 mode_to_access_flags(pa_entry->e_perm,
1406 0777,
1407 &access_bits);
1408 if (!access_bits)
1409 access_bits =
1410 SET_MINIMUM_RIGHTS;
1411 posix_acl_release(posix_acls);
1412 goto check_access_bits;
1413 }
1414 }
1415 }
1416 if (!IS_ERR_OR_NULL(posix_acls))
1417 posix_acl_release(posix_acls);
1418 }
1419
1420 if (!found) {
1421 if (others_ace) {
1422 ace = others_ace;
1423 } else {
1424 ksmbd_debug(SMB, "Can't find corresponding sid\n");
1425 rc = -EACCES;
1426 goto err_out;
1427 }
1428 }
1429
1430 switch (ace->type) {
1431 case ACCESS_ALLOWED_ACE_TYPE:
1432 access_bits = le32_to_cpu(ace->access_req);
1433 break;
1434 case ACCESS_DENIED_ACE_TYPE:
1435 case ACCESS_DENIED_CALLBACK_ACE_TYPE:
1436 access_bits = le32_to_cpu(~ace->access_req);
1437 break;
1438 }
1439
1440 check_access_bits:
1441 if (granted &
1442 ~(access_bits | FILE_READ_ATTRIBUTES | READ_CONTROL | WRITE_DAC | DELETE)) {
1443 ksmbd_debug(SMB, "Access denied with winACL, granted : %x, access_req : %x\n",
1444 granted, le32_to_cpu(ace->access_req));
1445 rc = -EACCES;
1446 goto err_out;
1447 }
1448
1449 *pdaccess = cpu_to_le32(granted);
1450 err_out:
1451 kfree(pntsd);
1452 return rc;
1453 }
1454
set_info_sec(struct ksmbd_conn * conn,struct ksmbd_tree_connect * tcon,const struct path * path,struct smb_ntsd * pntsd,int ntsd_len,bool type_check,bool get_write)1455 int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
1456 const struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
1457 bool type_check, bool get_write)
1458 {
1459 int rc;
1460 struct smb_fattr fattr = {{0}};
1461 struct inode *inode = d_inode(path->dentry);
1462 struct mnt_idmap *idmap = mnt_idmap(path->mnt);
1463 struct iattr newattrs;
1464
1465 fattr.cf_uid = INVALID_UID;
1466 fattr.cf_gid = INVALID_GID;
1467 fattr.cf_mode = inode->i_mode;
1468
1469 rc = parse_sec_desc(idmap, pntsd, ntsd_len, &fattr);
1470 if (rc)
1471 goto out;
1472
1473 newattrs.ia_valid = ATTR_CTIME;
1474 if (!uid_eq(fattr.cf_uid, INVALID_UID)) {
1475 newattrs.ia_valid |= ATTR_UID;
1476 newattrs.ia_uid = fattr.cf_uid;
1477 }
1478 if (!gid_eq(fattr.cf_gid, INVALID_GID)) {
1479 newattrs.ia_valid |= ATTR_GID;
1480 newattrs.ia_gid = fattr.cf_gid;
1481 }
1482 newattrs.ia_valid |= ATTR_MODE;
1483 newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777);
1484
1485 ksmbd_vfs_remove_acl_xattrs(idmap, path);
1486 /* Update posix acls */
1487 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) {
1488 rc = set_posix_acl(idmap, path->dentry,
1489 ACL_TYPE_ACCESS, fattr.cf_acls);
1490 if (rc < 0)
1491 ksmbd_debug(SMB,
1492 "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
1493 rc);
1494 if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) {
1495 rc = set_posix_acl(idmap, path->dentry,
1496 ACL_TYPE_DEFAULT, fattr.cf_dacls);
1497 if (rc)
1498 ksmbd_debug(SMB,
1499 "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
1500 rc);
1501 }
1502 }
1503
1504 inode_lock(inode);
1505 rc = notify_change(idmap, path->dentry, &newattrs, NULL);
1506 inode_unlock(inode);
1507 if (rc)
1508 goto out;
1509
1510 /* Check it only calling from SD BUFFER context */
1511 if (type_check && !(le16_to_cpu(pntsd->type) & DACL_PRESENT))
1512 goto out;
1513
1514 if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) {
1515 /* Update WinACL in xattr */
1516 ksmbd_vfs_remove_sd_xattrs(idmap, path);
1517 ksmbd_vfs_set_sd_xattr(conn, idmap, path, pntsd, ntsd_len,
1518 get_write);
1519 }
1520
1521 out:
1522 posix_acl_release(fattr.cf_acls);
1523 posix_acl_release(fattr.cf_dacls);
1524 return rc;
1525 }
1526
ksmbd_init_domain(u32 * sub_auth)1527 void ksmbd_init_domain(u32 *sub_auth)
1528 {
1529 int i;
1530
1531 memcpy(&server_conf.domain_sid, &domain, sizeof(struct smb_sid));
1532 for (i = 0; i < 3; ++i)
1533 server_conf.domain_sid.sub_auth[i + 1] = cpu_to_le32(sub_auth[i]);
1534 }
1535