xref: /openbmc/linux/drivers/md/dm-ima.c (revision f1288bdb)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2021 Microsoft Corporation
4  *
5  * Author: Tushar Sugandhi <tusharsu@linux.microsoft.com>
6  *
7  * File: dm-ima.c
8  *       Enables IMA measurements for DM targets
9  */
10 
11 #include "dm-core.h"
12 #include "dm-ima.h"
13 
14 #include <linux/ima.h>
15 #include <linux/sched/mm.h>
16 #include <crypto/hash.h>
17 #include <linux/crypto.h>
18 #include <crypto/hash_info.h>
19 
20 #define DM_MSG_PREFIX "ima"
21 
22 /*
23  * Internal function to prefix separator characters in input buffer with escape
24  * character, so that they don't interfere with the construction of key-value pairs,
25  * and clients can split the key1=val1,key2=val2,key3=val3; pairs properly.
26  */
27 static void fix_separator_chars(char **buf)
28 {
29 	int l = strlen(*buf);
30 	int i, j, sp = 0;
31 
32 	for (i = 0; i < l; i++)
33 		if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
34 			sp++;
35 
36 	if (!sp)
37 		return;
38 
39 	for (i = l-1, j = i+sp; i >= 0; i--) {
40 		(*buf)[j--] = (*buf)[i];
41 		if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
42 			(*buf)[j--] = '\\';
43 	}
44 }
45 
46 /*
47  * Internal function to allocate memory for IMA measurements.
48  */
49 static void *dm_ima_alloc(size_t len, gfp_t flags, bool noio)
50 {
51 	unsigned int noio_flag;
52 	void *ptr;
53 
54 	if (noio)
55 		noio_flag = memalloc_noio_save();
56 
57 	ptr = kzalloc(len, flags);
58 
59 	if (noio)
60 		memalloc_noio_restore(noio_flag);
61 
62 	return ptr;
63 }
64 
65 /*
66  * Internal function to allocate and copy name and uuid for IMA measurements.
67  */
68 static int dm_ima_alloc_and_copy_name_uuid(struct mapped_device *md, char **dev_name,
69 					   char **dev_uuid, bool noio)
70 {
71 	int r;
72 	*dev_name = dm_ima_alloc(DM_NAME_LEN*2, GFP_KERNEL, noio);
73 	if (!(*dev_name)) {
74 		r = -ENOMEM;
75 		goto error;
76 	}
77 
78 	*dev_uuid = dm_ima_alloc(DM_UUID_LEN*2, GFP_KERNEL, noio);
79 	if (!(*dev_uuid)) {
80 		r = -ENOMEM;
81 		goto error;
82 	}
83 
84 	r = dm_copy_name_and_uuid(md, *dev_name, *dev_uuid);
85 	if (r)
86 		goto error;
87 
88 	fix_separator_chars(dev_name);
89 	fix_separator_chars(dev_uuid);
90 
91 	return 0;
92 error:
93 	kfree(*dev_name);
94 	kfree(*dev_uuid);
95 	*dev_name = NULL;
96 	*dev_uuid = NULL;
97 	return r;
98 }
99 
100 /*
101  * Internal function to allocate and copy device data for IMA measurements.
102  */
103 static int dm_ima_alloc_and_copy_device_data(struct mapped_device *md, char **device_data,
104 					     unsigned int num_targets, bool noio)
105 {
106 	char *dev_name = NULL, *dev_uuid = NULL;
107 	int r;
108 
109 	r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
110 	if (r)
111 		return r;
112 
113 	*device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
114 	if (!(*device_data)) {
115 		r = -ENOMEM;
116 		goto error;
117 	}
118 
119 	scnprintf(*device_data, DM_IMA_DEVICE_BUF_LEN,
120 		  "name=%s,uuid=%s,major=%d,minor=%d,minor_count=%d,num_targets=%u;",
121 		  dev_name, dev_uuid, md->disk->major, md->disk->first_minor,
122 		  md->disk->minors, num_targets);
123 error:
124 	kfree(dev_name);
125 	kfree(dev_uuid);
126 	return r;
127 }
128 
129 /*
130  * Internal wrapper function to call IMA to measure DM data.
131  */
132 static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len,
133 				bool noio)
134 {
135 	unsigned int noio_flag;
136 
137 	if (noio)
138 		noio_flag = memalloc_noio_save();
139 
140 	ima_measure_critical_data(DM_NAME, event_name, buf, buf_len,
141 				  false, NULL, 0);
142 
143 	if (noio)
144 		memalloc_noio_restore(noio_flag);
145 }
146 
147 /*
148  * Internal function to allocate and copy current device capacity for IMA measurements.
149  */
150 static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **capacity_str,
151 					      bool noio)
152 {
153 	sector_t capacity;
154 
155 	capacity = get_capacity(md->disk);
156 
157 	*capacity_str = dm_ima_alloc(DM_IMA_DEVICE_CAPACITY_BUF_LEN, GFP_KERNEL, noio);
158 	if (!(*capacity_str))
159 		return -ENOMEM;
160 
161 	scnprintf(*capacity_str, DM_IMA_DEVICE_BUF_LEN, "current_device_capacity=%llu;",
162 		  capacity);
163 
164 	return 0;
165 }
166 
167 /*
168  * Initialize/reset the dm ima related data structure variables.
169  */
170 void dm_ima_reset_data(struct mapped_device *md)
171 {
172 	memset(&(md->ima), 0, sizeof(md->ima));
173 	md->ima.dm_version_str_len = strlen(DM_IMA_VERSION_STR);
174 }
175 
176 /*
177  * Build up the IMA data for each target, and finally measure.
178  */
179 void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags)
180 {
181 	size_t device_data_buf_len, target_metadata_buf_len, target_data_buf_len, l = 0;
182 	char *target_metadata_buf = NULL, *target_data_buf = NULL, *digest_buf = NULL;
183 	char *ima_buf = NULL, *device_data_buf = NULL;
184 	int digest_size, last_target_measured = -1, r;
185 	status_type_t type = STATUSTYPE_IMA;
186 	size_t cur_total_buf_len = 0;
187 	unsigned int num_targets, i;
188 	SHASH_DESC_ON_STACK(shash, NULL);
189 	struct crypto_shash *tfm = NULL;
190 	u8 *digest = NULL;
191 	bool noio = false;
192 	/*
193 	 * In below hash_alg_prefix_len assignment +1 is for the additional char (':'),
194 	 * when prefixing the hash value with the hash algorithm name. e.g. sha256:<hash_value>.
195 	 */
196 	const size_t hash_alg_prefix_len = strlen(DM_IMA_TABLE_HASH_ALG) + 1;
197 	char table_load_event_name[] = "dm_table_load";
198 
199 	ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, GFP_KERNEL, noio);
200 	if (!ima_buf)
201 		return;
202 
203 	target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, GFP_KERNEL, noio);
204 	if (!target_metadata_buf)
205 		goto error;
206 
207 	target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, GFP_KERNEL, noio);
208 	if (!target_data_buf)
209 		goto error;
210 
211 	num_targets = table->num_targets;
212 
213 	if (dm_ima_alloc_and_copy_device_data(table->md, &device_data_buf, num_targets, noio))
214 		goto error;
215 
216 	tfm = crypto_alloc_shash(DM_IMA_TABLE_HASH_ALG, 0, 0);
217 	if (IS_ERR(tfm))
218 		goto error;
219 
220 	shash->tfm = tfm;
221 	digest_size = crypto_shash_digestsize(tfm);
222 	digest = dm_ima_alloc(digest_size, GFP_KERNEL, noio);
223 	if (!digest)
224 		goto error;
225 
226 	r = crypto_shash_init(shash);
227 	if (r)
228 		goto error;
229 
230 	memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
231 	l += table->md->ima.dm_version_str_len;
232 
233 	device_data_buf_len = strlen(device_data_buf);
234 	memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
235 	l += device_data_buf_len;
236 
237 	for (i = 0; i < num_targets; i++) {
238 		struct dm_target *ti = dm_table_get_target(table, i);
239 
240 		last_target_measured = 0;
241 
242 		/*
243 		 * First retrieve the target metadata.
244 		 */
245 		scnprintf(target_metadata_buf, DM_IMA_TARGET_METADATA_BUF_LEN,
246 			  "target_index=%d,target_begin=%llu,target_len=%llu,",
247 			  i, ti->begin, ti->len);
248 		target_metadata_buf_len = strlen(target_metadata_buf);
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  */
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 		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 		l = strlen(device_table_data);
456 
457 	}
458 
459 	capacity_len = strlen(capacity_str);
460 	memcpy(device_table_data + l, capacity_str, capacity_len);
461 	l += capacity_len;
462 
463 	dm_ima_measure_data("dm_device_resume", device_table_data, l, noio);
464 
465 	kfree(dev_name);
466 	kfree(dev_uuid);
467 error:
468 	kfree(capacity_str);
469 	kfree(device_table_data);
470 }
471 
472 /*
473  * Measure IMA data on remove.
474  */
475 void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
476 {
477 	char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
478 	char active_table_str[] = "active_table_hash=";
479 	char inactive_table_str[] = "inactive_table_hash=";
480 	char device_active_str[] = "device_active_metadata=";
481 	char device_inactive_str[] = "device_inactive_metadata=";
482 	char remove_all_str[] = "remove_all=";
483 	unsigned int active_table_len = strlen(active_table_str);
484 	unsigned int inactive_table_len = strlen(inactive_table_str);
485 	unsigned int device_active_len = strlen(device_active_str);
486 	unsigned int device_inactive_len = strlen(device_inactive_str);
487 	unsigned int remove_all_len = strlen(remove_all_str);
488 	unsigned int capacity_len = 0;
489 	unsigned int l = 0;
490 	bool noio = true;
491 	bool nodata = true;
492 	int r;
493 
494 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, GFP_KERNEL, noio);
495 	if (!device_table_data)
496 		goto exit;
497 
498 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
499 	if (r) {
500 		kfree(device_table_data);
501 		goto exit;
502 	}
503 
504 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
505 	l += md->ima.dm_version_str_len;
506 
507 	if (md->ima.active_table.device_metadata) {
508 		memcpy(device_table_data + l, device_active_str, device_active_len);
509 		l += device_active_len;
510 
511 		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
512 		       md->ima.active_table.device_metadata_len);
513 		l += md->ima.active_table.device_metadata_len;
514 
515 		nodata = false;
516 	}
517 
518 	if (md->ima.inactive_table.device_metadata) {
519 		memcpy(device_table_data + l, device_inactive_str, device_inactive_len);
520 		l += device_inactive_len;
521 
522 		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
523 		       md->ima.inactive_table.device_metadata_len);
524 		l += md->ima.inactive_table.device_metadata_len;
525 
526 		nodata = false;
527 	}
528 
529 	if (md->ima.active_table.hash) {
530 		memcpy(device_table_data + l, active_table_str, active_table_len);
531 		l += active_table_len;
532 
533 		memcpy(device_table_data + l, md->ima.active_table.hash,
534 			   md->ima.active_table.hash_len);
535 		l += md->ima.active_table.hash_len;
536 
537 		memcpy(device_table_data + l, ",", 1);
538 		l++;
539 
540 		nodata = false;
541 	}
542 
543 	if (md->ima.inactive_table.hash) {
544 		memcpy(device_table_data + l, inactive_table_str, inactive_table_len);
545 		l += inactive_table_len;
546 
547 		memcpy(device_table_data + l, md->ima.inactive_table.hash,
548 		       md->ima.inactive_table.hash_len);
549 		l += md->ima.inactive_table.hash_len;
550 
551 		memcpy(device_table_data + l, ",", 1);
552 		l++;
553 
554 		nodata = false;
555 	}
556 	/*
557 	 * In case both active and inactive tables, and corresponding
558 	 * device metadata is cleared/missing - record the name and uuid
559 	 * in IMA measurements.
560 	 */
561 	if (nodata) {
562 		if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
563 			goto error;
564 
565 		scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
566 			  "%sname=%s,uuid=%s;device_remove=no_data;",
567 			  DM_IMA_VERSION_STR, dev_name, dev_uuid);
568 		l = strlen(device_table_data);
569 	}
570 
571 	memcpy(device_table_data + l, remove_all_str, remove_all_len);
572 	l += remove_all_len;
573 	memcpy(device_table_data + l, remove_all ? "y;" : "n;", 2);
574 	l += 2;
575 
576 	capacity_len = strlen(capacity_str);
577 	memcpy(device_table_data + l, capacity_str, capacity_len);
578 	l += capacity_len;
579 
580 	dm_ima_measure_data("dm_device_remove", device_table_data, l, noio);
581 
582 error:
583 	kfree(device_table_data);
584 	kfree(capacity_str);
585 exit:
586 	kfree(md->ima.active_table.device_metadata);
587 
588 	if (md->ima.active_table.device_metadata !=
589 	    md->ima.inactive_table.device_metadata)
590 		kfree(md->ima.inactive_table.device_metadata);
591 
592 	kfree(md->ima.active_table.hash);
593 
594 	if (md->ima.active_table.hash != md->ima.inactive_table.hash)
595 		kfree(md->ima.inactive_table.hash);
596 
597 	dm_ima_reset_data(md);
598 
599 	kfree(dev_name);
600 	kfree(dev_uuid);
601 }
602 
603 /*
604  * Measure ima data on table clear.
605  */
606 void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
607 {
608 	unsigned int l = 0, capacity_len = 0;
609 	char *device_table_data = NULL, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
610 	char inactive_str[] = "inactive_table_hash=";
611 	unsigned int inactive_len = strlen(inactive_str);
612 	bool noio = true;
613 	bool nodata = true;
614 	int r;
615 
616 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
617 	if (!device_table_data)
618 		return;
619 
620 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
621 	if (r)
622 		goto error1;
623 
624 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
625 	l += md->ima.dm_version_str_len;
626 
627 	if (md->ima.inactive_table.device_metadata_len &&
628 	    md->ima.inactive_table.hash_len) {
629 		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
630 		       md->ima.inactive_table.device_metadata_len);
631 		l += md->ima.inactive_table.device_metadata_len;
632 
633 		memcpy(device_table_data + l, inactive_str, inactive_len);
634 		l += inactive_len;
635 
636 		memcpy(device_table_data + l, md->ima.inactive_table.hash,
637 			   md->ima.inactive_table.hash_len);
638 
639 		l += md->ima.inactive_table.hash_len;
640 
641 		memcpy(device_table_data + l, ";", 1);
642 		l++;
643 
644 		nodata = false;
645 	}
646 
647 	if (nodata) {
648 		if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
649 			goto error2;
650 
651 		scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
652 			  "%sname=%s,uuid=%s;table_clear=no_data;",
653 			   DM_IMA_VERSION_STR, dev_name, dev_uuid);
654 		l = strlen(device_table_data);
655 	}
656 
657 	capacity_len = strlen(capacity_str);
658 	memcpy(device_table_data + l, capacity_str, capacity_len);
659 	l += capacity_len;
660 
661 	dm_ima_measure_data("dm_table_clear", device_table_data, l, noio);
662 
663 	if (new_map) {
664 		if (md->ima.inactive_table.hash &&
665 		    md->ima.inactive_table.hash != md->ima.active_table.hash)
666 			kfree(md->ima.inactive_table.hash);
667 
668 		md->ima.inactive_table.hash = NULL;
669 		md->ima.inactive_table.hash_len = 0;
670 
671 		if (md->ima.inactive_table.device_metadata &&
672 		    md->ima.inactive_table.device_metadata != md->ima.active_table.device_metadata)
673 			kfree(md->ima.inactive_table.device_metadata);
674 
675 		md->ima.inactive_table.device_metadata = NULL;
676 		md->ima.inactive_table.device_metadata_len = 0;
677 		md->ima.inactive_table.num_targets = 0;
678 
679 		if (md->ima.active_table.hash) {
680 			md->ima.inactive_table.hash = md->ima.active_table.hash;
681 			md->ima.inactive_table.hash_len = md->ima.active_table.hash_len;
682 		}
683 
684 		if (md->ima.active_table.device_metadata) {
685 			md->ima.inactive_table.device_metadata =
686 				md->ima.active_table.device_metadata;
687 			md->ima.inactive_table.device_metadata_len =
688 				md->ima.active_table.device_metadata_len;
689 			md->ima.inactive_table.num_targets =
690 				md->ima.active_table.num_targets;
691 		}
692 	}
693 
694 	kfree(dev_name);
695 	kfree(dev_uuid);
696 error2:
697 	kfree(capacity_str);
698 error1:
699 	kfree(device_table_data);
700 }
701 
702 /*
703  * Measure IMA data on device rename.
704  */
705 void dm_ima_measure_on_device_rename(struct mapped_device *md)
706 {
707 	char *old_device_data = NULL, *new_device_data = NULL, *combined_device_data = NULL;
708 	char *new_dev_name = NULL, *new_dev_uuid = NULL, *capacity_str = NULL;
709 	bool noio = true;
710 	int r;
711 
712 	if (dm_ima_alloc_and_copy_device_data(md, &new_device_data,
713 					      md->ima.active_table.num_targets, noio))
714 		return;
715 
716 	if (dm_ima_alloc_and_copy_name_uuid(md, &new_dev_name, &new_dev_uuid, noio))
717 		goto error;
718 
719 	combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, GFP_KERNEL, noio);
720 	if (!combined_device_data)
721 		goto error;
722 
723 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
724 	if (r)
725 		goto error;
726 
727 	old_device_data = md->ima.active_table.device_metadata;
728 
729 	md->ima.active_table.device_metadata = new_device_data;
730 	md->ima.active_table.device_metadata_len = strlen(new_device_data);
731 
732 	scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2,
733 		  "%s%snew_name=%s,new_uuid=%s;%s", DM_IMA_VERSION_STR, old_device_data,
734 		  new_dev_name, new_dev_uuid, capacity_str);
735 
736 	dm_ima_measure_data("dm_device_rename", combined_device_data, strlen(combined_device_data),
737 			    noio);
738 
739 	goto exit;
740 
741 error:
742 	kfree(new_device_data);
743 exit:
744 	kfree(capacity_str);
745 	kfree(combined_device_data);
746 	kfree(old_device_data);
747 	kfree(new_dev_name);
748 	kfree(new_dev_uuid);
749 }
750