xref: /linux/drivers/md/dm-ima.c (revision 0074281bb6316108e0cff094bd4db78ab3eee236)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2021 Microsoft Corporation
4  *
5  * Author: Tushar Sugandhi <tusharsu@linux.microsoft.com>
6  *
7  * Enables IMA measurements for DM targets
8  */
9 
10 #include "dm-core.h"
11 #include "dm-ima.h"
12 
13 #include <linux/ima.h>
14 #include <linux/sched/mm.h>
15 #include <crypto/hash.h>
16 #include <linux/crypto.h>
17 #include <crypto/hash_info.h>
18 
19 #define DM_MSG_PREFIX "ima"
20 
21 /*
22  * Internal function to prefix separator characters in input buffer with escape
23  * character, so that they don't interfere with the construction of key-value pairs,
24  * and clients can split the key1=val1,key2=val2,key3=val3; pairs properly.
25  */
fix_separator_chars(char ** buf)26 static void fix_separator_chars(char **buf)
27 {
28 	int l = strlen(*buf);
29 	int i, j, sp = 0;
30 
31 	for (i = 0; i < l; i++)
32 		if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
33 			sp++;
34 
35 	if (!sp)
36 		return;
37 
38 	for (i = l-1, j = i+sp; i >= 0; i--) {
39 		(*buf)[j--] = (*buf)[i];
40 		if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
41 			(*buf)[j--] = '\\';
42 	}
43 }
44 
45 /*
46  * Internal function to allocate memory for IMA measurements.
47  */
dm_ima_alloc(size_t len,gfp_t flags,bool noio)48 static void *dm_ima_alloc(size_t len, gfp_t flags, bool noio)
49 {
50 	unsigned int noio_flag;
51 	void *ptr;
52 
53 	if (noio)
54 		noio_flag = memalloc_noio_save();
55 
56 	ptr = kzalloc(len, flags);
57 
58 	if (noio)
59 		memalloc_noio_restore(noio_flag);
60 
61 	return ptr;
62 }
63 
64 /*
65  * Internal function to allocate and copy name and uuid for IMA measurements.
66  */
dm_ima_alloc_and_copy_name_uuid(struct mapped_device * md,char ** dev_name,char ** dev_uuid,bool noio)67 static int dm_ima_alloc_and_copy_name_uuid(struct mapped_device *md, char **dev_name,
68 					   char **dev_uuid, bool noio)
69 {
70 	int r;
71 	*dev_name = dm_ima_alloc(DM_NAME_LEN*2, GFP_KERNEL, noio);
72 	if (!(*dev_name)) {
73 		r = -ENOMEM;
74 		goto error;
75 	}
76 
77 	*dev_uuid = dm_ima_alloc(DM_UUID_LEN*2, GFP_KERNEL, noio);
78 	if (!(*dev_uuid)) {
79 		r = -ENOMEM;
80 		goto error;
81 	}
82 
83 	r = dm_copy_name_and_uuid(md, *dev_name, *dev_uuid);
84 	if (r)
85 		goto error;
86 
87 	fix_separator_chars(dev_name);
88 	fix_separator_chars(dev_uuid);
89 
90 	return 0;
91 error:
92 	kfree(*dev_name);
93 	kfree(*dev_uuid);
94 	*dev_name = NULL;
95 	*dev_uuid = NULL;
96 	return r;
97 }
98 
99 /*
100  * Internal function to allocate and copy device data for IMA measurements.
101  */
dm_ima_alloc_and_copy_device_data(struct mapped_device * md,char ** device_data,unsigned int num_targets,bool noio)102 static int dm_ima_alloc_and_copy_device_data(struct mapped_device *md, char **device_data,
103 					     unsigned int num_targets, bool noio)
104 {
105 	char *dev_name = NULL, *dev_uuid = NULL;
106 	int r;
107 
108 	r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
109 	if (r)
110 		return r;
111 
112 	*device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
113 	if (!(*device_data)) {
114 		r = -ENOMEM;
115 		goto error;
116 	}
117 
118 	scnprintf(*device_data, DM_IMA_DEVICE_BUF_LEN,
119 		  "name=%s,uuid=%s,major=%d,minor=%d,minor_count=%d,num_targets=%u;",
120 		  dev_name, dev_uuid, md->disk->major, md->disk->first_minor,
121 		  md->disk->minors, num_targets);
122 error:
123 	kfree(dev_name);
124 	kfree(dev_uuid);
125 	return r;
126 }
127 
128 /*
129  * Internal wrapper function to call IMA to measure DM data.
130  */
dm_ima_measure_data(const char * event_name,const void * buf,size_t buf_len,bool noio)131 static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len,
132 				bool noio)
133 {
134 	unsigned int noio_flag;
135 
136 	if (noio)
137 		noio_flag = memalloc_noio_save();
138 
139 	ima_measure_critical_data(DM_NAME, event_name, buf, buf_len,
140 				  false, NULL, 0);
141 
142 	if (noio)
143 		memalloc_noio_restore(noio_flag);
144 }
145 
146 /*
147  * Internal function to allocate and copy current device capacity for IMA measurements.
148  */
dm_ima_alloc_and_copy_capacity_str(struct mapped_device * md,char ** capacity_str,bool noio)149 static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **capacity_str,
150 					      bool noio)
151 {
152 	sector_t capacity;
153 
154 	capacity = get_capacity(md->disk);
155 
156 	*capacity_str = dm_ima_alloc(DM_IMA_DEVICE_CAPACITY_BUF_LEN, GFP_KERNEL, noio);
157 	if (!(*capacity_str))
158 		return -ENOMEM;
159 
160 	scnprintf(*capacity_str, DM_IMA_DEVICE_BUF_LEN, "current_device_capacity=%llu;",
161 		  capacity);
162 
163 	return 0;
164 }
165 
166 /*
167  * Initialize/reset the dm ima related data structure variables.
168  */
dm_ima_reset_data(struct mapped_device * md)169 void dm_ima_reset_data(struct mapped_device *md)
170 {
171 	memset(&(md->ima), 0, sizeof(md->ima));
172 	md->ima.dm_version_str_len = strlen(DM_IMA_VERSION_STR);
173 }
174 
175 /*
176  * Build up the IMA data for each target, and finally measure.
177  */
dm_ima_measure_on_table_load(struct dm_table * table,unsigned int status_flags)178 void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags)
179 {
180 	size_t device_data_buf_len, target_metadata_buf_len, target_data_buf_len, l = 0;
181 	char *target_metadata_buf = NULL, *target_data_buf = NULL, *digest_buf = NULL;
182 	char *ima_buf = NULL, *device_data_buf = NULL;
183 	int digest_size, last_target_measured = -1, r;
184 	status_type_t type = STATUSTYPE_IMA;
185 	size_t cur_total_buf_len = 0;
186 	unsigned int num_targets, i;
187 	SHASH_DESC_ON_STACK(shash, NULL);
188 	struct crypto_shash *tfm = NULL;
189 	u8 *digest = NULL;
190 	bool noio = false;
191 	/*
192 	 * In below hash_alg_prefix_len assignment +1 is for the additional char (':'),
193 	 * when prefixing the hash value with the hash algorithm name. e.g. sha256:<hash_value>.
194 	 */
195 	const size_t hash_alg_prefix_len = strlen(DM_IMA_TABLE_HASH_ALG) + 1;
196 	char table_load_event_name[] = "dm_table_load";
197 
198 	ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, GFP_KERNEL, noio);
199 	if (!ima_buf)
200 		return;
201 
202 	target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, GFP_KERNEL, noio);
203 	if (!target_metadata_buf)
204 		goto error;
205 
206 	target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, GFP_KERNEL, noio);
207 	if (!target_data_buf)
208 		goto error;
209 
210 	num_targets = table->num_targets;
211 
212 	if (dm_ima_alloc_and_copy_device_data(table->md, &device_data_buf, num_targets, noio))
213 		goto error;
214 
215 	tfm = crypto_alloc_shash(DM_IMA_TABLE_HASH_ALG, 0, 0);
216 	if (IS_ERR(tfm))
217 		goto error;
218 
219 	shash->tfm = tfm;
220 	digest_size = crypto_shash_digestsize(tfm);
221 	digest = dm_ima_alloc(digest_size, GFP_KERNEL, noio);
222 	if (!digest)
223 		goto error;
224 
225 	r = crypto_shash_init(shash);
226 	if (r)
227 		goto error;
228 
229 	memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
230 	l += table->md->ima.dm_version_str_len;
231 
232 	device_data_buf_len = strlen(device_data_buf);
233 	memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
234 	l += device_data_buf_len;
235 
236 	for (i = 0; i < num_targets; i++) {
237 		struct dm_target *ti = dm_table_get_target(table, i);
238 
239 		last_target_measured = 0;
240 
241 		/*
242 		 * First retrieve the target metadata.
243 		 */
244 		target_metadata_buf_len =
245 			scnprintf(target_metadata_buf,
246 				  DM_IMA_TARGET_METADATA_BUF_LEN,
247 				  "target_index=%d,target_begin=%llu,target_len=%llu,",
248 				  i, ti->begin, ti->len);
249 
250 		/*
251 		 * Then retrieve the actual target data.
252 		 */
253 		if (ti->type->status)
254 			ti->type->status(ti, type, status_flags, target_data_buf,
255 					 DM_IMA_TARGET_DATA_BUF_LEN);
256 		else
257 			target_data_buf[0] = '\0';
258 
259 		target_data_buf_len = strlen(target_data_buf);
260 
261 		/*
262 		 * Check if the total data can fit into the IMA buffer.
263 		 */
264 		cur_total_buf_len = l + target_metadata_buf_len + target_data_buf_len;
265 
266 		/*
267 		 * IMA measurements for DM targets are best-effort.
268 		 * If the total data buffered so far, including the current target,
269 		 * is too large to fit into DM_IMA_MEASUREMENT_BUF_LEN, measure what
270 		 * we have in the current buffer, and continue measuring the remaining
271 		 * targets by prefixing the device metadata again.
272 		 */
273 		if (unlikely(cur_total_buf_len >= DM_IMA_MEASUREMENT_BUF_LEN)) {
274 			dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
275 			r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
276 			if (r < 0)
277 				goto error;
278 
279 			memset(ima_buf, 0, DM_IMA_MEASUREMENT_BUF_LEN);
280 			l = 0;
281 
282 			/*
283 			 * Each new "dm_table_load" entry in IMA log should have device data
284 			 * prefix, so that multiple records from the same "dm_table_load" for
285 			 * a given device can be linked together.
286 			 */
287 			memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
288 			l += table->md->ima.dm_version_str_len;
289 
290 			memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
291 			l += device_data_buf_len;
292 
293 			/*
294 			 * If this iteration of the for loop turns out to be the last target
295 			 * in the table, dm_ima_measure_data("dm_table_load", ...) doesn't need
296 			 * to be called again, just the hash needs to be finalized.
297 			 * "last_target_measured" tracks this state.
298 			 */
299 			last_target_measured = 1;
300 		}
301 
302 		/*
303 		 * Fill-in all the target metadata, so that multiple targets for the same
304 		 * device can be linked together.
305 		 */
306 		memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len);
307 		l += target_metadata_buf_len;
308 
309 		memcpy(ima_buf + l, target_data_buf, target_data_buf_len);
310 		l += target_data_buf_len;
311 	}
312 
313 	if (!last_target_measured) {
314 		dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
315 
316 		r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
317 		if (r < 0)
318 			goto error;
319 	}
320 
321 	/*
322 	 * Finalize the table hash, and store it in table->md->ima.inactive_table.hash,
323 	 * so that the table data can be verified against the future device state change
324 	 * events, e.g. resume, rename, remove, table-clear etc.
325 	 */
326 	r = crypto_shash_final(shash, digest);
327 	if (r < 0)
328 		goto error;
329 
330 	digest_buf = dm_ima_alloc((digest_size*2) + hash_alg_prefix_len + 1, GFP_KERNEL, noio);
331 
332 	if (!digest_buf)
333 		goto error;
334 
335 	snprintf(digest_buf, hash_alg_prefix_len + 1, "%s:", DM_IMA_TABLE_HASH_ALG);
336 
337 	for (i = 0; i < digest_size; i++)
338 		snprintf((digest_buf + hash_alg_prefix_len + (i*2)), 3, "%02x", digest[i]);
339 
340 	if (table->md->ima.active_table.hash != table->md->ima.inactive_table.hash)
341 		kfree(table->md->ima.inactive_table.hash);
342 
343 	table->md->ima.inactive_table.hash = digest_buf;
344 	table->md->ima.inactive_table.hash_len = strlen(digest_buf);
345 	table->md->ima.inactive_table.num_targets = num_targets;
346 
347 	if (table->md->ima.active_table.device_metadata !=
348 	    table->md->ima.inactive_table.device_metadata)
349 		kfree(table->md->ima.inactive_table.device_metadata);
350 
351 	table->md->ima.inactive_table.device_metadata = device_data_buf;
352 	table->md->ima.inactive_table.device_metadata_len = device_data_buf_len;
353 
354 	goto exit;
355 error:
356 	kfree(digest_buf);
357 	kfree(device_data_buf);
358 exit:
359 	kfree(digest);
360 	if (tfm)
361 		crypto_free_shash(tfm);
362 	kfree(ima_buf);
363 	kfree(target_metadata_buf);
364 	kfree(target_data_buf);
365 }
366 
367 /*
368  * Measure IMA data on device resume.
369  */
dm_ima_measure_on_device_resume(struct mapped_device * md,bool swap)370 void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap)
371 {
372 	char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
373 	char active[] = "active_table_hash=";
374 	unsigned int active_len = strlen(active), capacity_len = 0;
375 	unsigned int l = 0;
376 	bool noio = true;
377 	bool nodata = true;
378 	int r;
379 
380 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
381 	if (!device_table_data)
382 		return;
383 
384 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
385 	if (r)
386 		goto error;
387 
388 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
389 	l += md->ima.dm_version_str_len;
390 
391 	if (swap) {
392 		if (md->ima.active_table.hash != md->ima.inactive_table.hash)
393 			kfree(md->ima.active_table.hash);
394 
395 		md->ima.active_table.hash = NULL;
396 		md->ima.active_table.hash_len = 0;
397 
398 		if (md->ima.active_table.device_metadata !=
399 		    md->ima.inactive_table.device_metadata)
400 			kfree(md->ima.active_table.device_metadata);
401 
402 		md->ima.active_table.device_metadata = NULL;
403 		md->ima.active_table.device_metadata_len = 0;
404 		md->ima.active_table.num_targets = 0;
405 
406 		if (md->ima.inactive_table.hash) {
407 			md->ima.active_table.hash = md->ima.inactive_table.hash;
408 			md->ima.active_table.hash_len = md->ima.inactive_table.hash_len;
409 			md->ima.inactive_table.hash = NULL;
410 			md->ima.inactive_table.hash_len = 0;
411 		}
412 
413 		if (md->ima.inactive_table.device_metadata) {
414 			md->ima.active_table.device_metadata =
415 				md->ima.inactive_table.device_metadata;
416 			md->ima.active_table.device_metadata_len =
417 				md->ima.inactive_table.device_metadata_len;
418 			md->ima.active_table.num_targets = md->ima.inactive_table.num_targets;
419 			md->ima.inactive_table.device_metadata = NULL;
420 			md->ima.inactive_table.device_metadata_len = 0;
421 			md->ima.inactive_table.num_targets = 0;
422 		}
423 	}
424 
425 	if (md->ima.active_table.device_metadata) {
426 		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
427 		       md->ima.active_table.device_metadata_len);
428 		l += md->ima.active_table.device_metadata_len;
429 
430 		nodata = false;
431 	}
432 
433 	if (md->ima.active_table.hash) {
434 		memcpy(device_table_data + l, active, active_len);
435 		l += active_len;
436 
437 		memcpy(device_table_data + l, md->ima.active_table.hash,
438 		       md->ima.active_table.hash_len);
439 		l += md->ima.active_table.hash_len;
440 
441 		memcpy(device_table_data + l, ";", 1);
442 		l++;
443 
444 		nodata = false;
445 	}
446 
447 	if (nodata) {
448 		r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
449 		if (r)
450 			goto error;
451 
452 		l = scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
453 			      "%sname=%s,uuid=%s;device_resume=no_data;",
454 			      DM_IMA_VERSION_STR, dev_name, dev_uuid);
455 	}
456 
457 	capacity_len = strlen(capacity_str);
458 	memcpy(device_table_data + l, capacity_str, capacity_len);
459 	l += capacity_len;
460 
461 	dm_ima_measure_data("dm_device_resume", device_table_data, l, noio);
462 
463 	kfree(dev_name);
464 	kfree(dev_uuid);
465 error:
466 	kfree(capacity_str);
467 	kfree(device_table_data);
468 }
469 
470 /*
471  * Measure IMA data on remove.
472  */
dm_ima_measure_on_device_remove(struct mapped_device * md,bool remove_all)473 void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
474 {
475 	char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
476 	char active_table_str[] = "active_table_hash=";
477 	char inactive_table_str[] = "inactive_table_hash=";
478 	char device_active_str[] = "device_active_metadata=";
479 	char device_inactive_str[] = "device_inactive_metadata=";
480 	char remove_all_str[] = "remove_all=";
481 	unsigned int active_table_len = strlen(active_table_str);
482 	unsigned int inactive_table_len = strlen(inactive_table_str);
483 	unsigned int device_active_len = strlen(device_active_str);
484 	unsigned int device_inactive_len = strlen(device_inactive_str);
485 	unsigned int remove_all_len = strlen(remove_all_str);
486 	unsigned int capacity_len = 0;
487 	unsigned int l = 0;
488 	bool noio = true;
489 	bool nodata = true;
490 	int r;
491 
492 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, GFP_KERNEL, noio);
493 	if (!device_table_data)
494 		goto exit;
495 
496 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
497 	if (r) {
498 		kfree(device_table_data);
499 		goto exit;
500 	}
501 
502 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
503 	l += md->ima.dm_version_str_len;
504 
505 	if (md->ima.active_table.device_metadata) {
506 		memcpy(device_table_data + l, device_active_str, device_active_len);
507 		l += device_active_len;
508 
509 		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
510 		       md->ima.active_table.device_metadata_len);
511 		l += md->ima.active_table.device_metadata_len;
512 
513 		nodata = false;
514 	}
515 
516 	if (md->ima.inactive_table.device_metadata) {
517 		memcpy(device_table_data + l, device_inactive_str, device_inactive_len);
518 		l += device_inactive_len;
519 
520 		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
521 		       md->ima.inactive_table.device_metadata_len);
522 		l += md->ima.inactive_table.device_metadata_len;
523 
524 		nodata = false;
525 	}
526 
527 	if (md->ima.active_table.hash) {
528 		memcpy(device_table_data + l, active_table_str, active_table_len);
529 		l += active_table_len;
530 
531 		memcpy(device_table_data + l, md->ima.active_table.hash,
532 			   md->ima.active_table.hash_len);
533 		l += md->ima.active_table.hash_len;
534 
535 		memcpy(device_table_data + l, ",", 1);
536 		l++;
537 
538 		nodata = false;
539 	}
540 
541 	if (md->ima.inactive_table.hash) {
542 		memcpy(device_table_data + l, inactive_table_str, inactive_table_len);
543 		l += inactive_table_len;
544 
545 		memcpy(device_table_data + l, md->ima.inactive_table.hash,
546 		       md->ima.inactive_table.hash_len);
547 		l += md->ima.inactive_table.hash_len;
548 
549 		memcpy(device_table_data + l, ",", 1);
550 		l++;
551 
552 		nodata = false;
553 	}
554 	/*
555 	 * In case both active and inactive tables, and corresponding
556 	 * device metadata is cleared/missing - record the name and uuid
557 	 * in IMA measurements.
558 	 */
559 	if (nodata) {
560 		if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
561 			goto error;
562 
563 		l = scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
564 			      "%sname=%s,uuid=%s;device_remove=no_data;",
565 			      DM_IMA_VERSION_STR, dev_name, dev_uuid);
566 	}
567 
568 	memcpy(device_table_data + l, remove_all_str, remove_all_len);
569 	l += remove_all_len;
570 	memcpy(device_table_data + l, remove_all ? "y;" : "n;", 2);
571 	l += 2;
572 
573 	capacity_len = strlen(capacity_str);
574 	memcpy(device_table_data + l, capacity_str, capacity_len);
575 	l += capacity_len;
576 
577 	dm_ima_measure_data("dm_device_remove", device_table_data, l, noio);
578 
579 error:
580 	kfree(device_table_data);
581 	kfree(capacity_str);
582 exit:
583 	kfree(md->ima.active_table.device_metadata);
584 
585 	if (md->ima.active_table.device_metadata !=
586 	    md->ima.inactive_table.device_metadata)
587 		kfree(md->ima.inactive_table.device_metadata);
588 
589 	kfree(md->ima.active_table.hash);
590 
591 	if (md->ima.active_table.hash != md->ima.inactive_table.hash)
592 		kfree(md->ima.inactive_table.hash);
593 
594 	dm_ima_reset_data(md);
595 
596 	kfree(dev_name);
597 	kfree(dev_uuid);
598 }
599 
600 /*
601  * Measure ima data on table clear.
602  */
dm_ima_measure_on_table_clear(struct mapped_device * md,bool new_map)603 void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
604 {
605 	unsigned int l = 0, capacity_len = 0;
606 	char *device_table_data = NULL, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
607 	char inactive_str[] = "inactive_table_hash=";
608 	unsigned int inactive_len = strlen(inactive_str);
609 	bool noio = true;
610 	bool nodata = true;
611 	int r;
612 
613 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
614 	if (!device_table_data)
615 		return;
616 
617 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
618 	if (r)
619 		goto error1;
620 
621 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
622 	l += md->ima.dm_version_str_len;
623 
624 	if (md->ima.inactive_table.device_metadata_len &&
625 	    md->ima.inactive_table.hash_len) {
626 		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
627 		       md->ima.inactive_table.device_metadata_len);
628 		l += md->ima.inactive_table.device_metadata_len;
629 
630 		memcpy(device_table_data + l, inactive_str, inactive_len);
631 		l += inactive_len;
632 
633 		memcpy(device_table_data + l, md->ima.inactive_table.hash,
634 			   md->ima.inactive_table.hash_len);
635 
636 		l += md->ima.inactive_table.hash_len;
637 
638 		memcpy(device_table_data + l, ";", 1);
639 		l++;
640 
641 		nodata = false;
642 	}
643 
644 	if (nodata) {
645 		if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
646 			goto error2;
647 
648 		l = scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
649 			      "%sname=%s,uuid=%s;table_clear=no_data;",
650 			      DM_IMA_VERSION_STR, dev_name, dev_uuid);
651 	}
652 
653 	capacity_len = strlen(capacity_str);
654 	memcpy(device_table_data + l, capacity_str, capacity_len);
655 	l += capacity_len;
656 
657 	dm_ima_measure_data("dm_table_clear", device_table_data, l, noio);
658 
659 	if (new_map) {
660 		if (md->ima.inactive_table.hash &&
661 		    md->ima.inactive_table.hash != md->ima.active_table.hash)
662 			kfree(md->ima.inactive_table.hash);
663 
664 		md->ima.inactive_table.hash = NULL;
665 		md->ima.inactive_table.hash_len = 0;
666 
667 		if (md->ima.inactive_table.device_metadata &&
668 		    md->ima.inactive_table.device_metadata != md->ima.active_table.device_metadata)
669 			kfree(md->ima.inactive_table.device_metadata);
670 
671 		md->ima.inactive_table.device_metadata = NULL;
672 		md->ima.inactive_table.device_metadata_len = 0;
673 		md->ima.inactive_table.num_targets = 0;
674 
675 		if (md->ima.active_table.hash) {
676 			md->ima.inactive_table.hash = md->ima.active_table.hash;
677 			md->ima.inactive_table.hash_len = md->ima.active_table.hash_len;
678 		}
679 
680 		if (md->ima.active_table.device_metadata) {
681 			md->ima.inactive_table.device_metadata =
682 				md->ima.active_table.device_metadata;
683 			md->ima.inactive_table.device_metadata_len =
684 				md->ima.active_table.device_metadata_len;
685 			md->ima.inactive_table.num_targets =
686 				md->ima.active_table.num_targets;
687 		}
688 	}
689 
690 	kfree(dev_name);
691 	kfree(dev_uuid);
692 error2:
693 	kfree(capacity_str);
694 error1:
695 	kfree(device_table_data);
696 }
697 
698 /*
699  * Measure IMA data on device rename.
700  */
dm_ima_measure_on_device_rename(struct mapped_device * md)701 void dm_ima_measure_on_device_rename(struct mapped_device *md)
702 {
703 	char *old_device_data = NULL, *new_device_data = NULL, *combined_device_data = NULL;
704 	char *new_dev_name = NULL, *new_dev_uuid = NULL, *capacity_str = NULL;
705 	bool noio = true;
706 	int r, len;
707 
708 	if (dm_ima_alloc_and_copy_device_data(md, &new_device_data,
709 					      md->ima.active_table.num_targets, noio))
710 		return;
711 
712 	if (dm_ima_alloc_and_copy_name_uuid(md, &new_dev_name, &new_dev_uuid, noio))
713 		goto error;
714 
715 	combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, GFP_KERNEL, noio);
716 	if (!combined_device_data)
717 		goto error;
718 
719 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
720 	if (r)
721 		goto error;
722 
723 	old_device_data = md->ima.active_table.device_metadata;
724 
725 	md->ima.active_table.device_metadata = new_device_data;
726 	md->ima.active_table.device_metadata_len = strlen(new_device_data);
727 
728 	len = scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2,
729 			"%s%snew_name=%s,new_uuid=%s;%s", DM_IMA_VERSION_STR, old_device_data,
730 			new_dev_name, new_dev_uuid, capacity_str);
731 
732 	dm_ima_measure_data("dm_device_rename", combined_device_data, len, noio);
733 
734 	goto exit;
735 
736 error:
737 	kfree(new_device_data);
738 exit:
739 	kfree(capacity_str);
740 	kfree(combined_device_data);
741 	kfree(old_device_data);
742 	kfree(new_dev_name);
743 	kfree(new_dev_uuid);
744 }
745