xref: /openbmc/linux/drivers/md/dm-ima.c (revision 7a010c3c)
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 <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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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 = dm_table_get_num_targets(table);
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 		if (!ti)
240 			goto error;
241 
242 		last_target_measured = 0;
243 
244 		/*
245 		 * First retrieve the target metadata.
246 		 */
247 		scnprintf(target_metadata_buf, DM_IMA_TARGET_METADATA_BUF_LEN,
248 			  "target_index=%d,target_begin=%llu,target_len=%llu,",
249 			  i, ti->begin, ti->len);
250 		target_metadata_buf_len = strlen(target_metadata_buf);
251 
252 		/*
253 		 * Then retrieve the actual target data.
254 		 */
255 		if (ti->type->status)
256 			ti->type->status(ti, type, status_flags, target_data_buf,
257 					 DM_IMA_TARGET_DATA_BUF_LEN);
258 		else
259 			target_data_buf[0] = '\0';
260 
261 		target_data_buf_len = strlen(target_data_buf);
262 
263 		/*
264 		 * Check if the total data can fit into the IMA buffer.
265 		 */
266 		cur_total_buf_len = l + target_metadata_buf_len + target_data_buf_len;
267 
268 		/*
269 		 * IMA measurements for DM targets are best-effort.
270 		 * If the total data buffered so far, including the current target,
271 		 * is too large to fit into DM_IMA_MEASUREMENT_BUF_LEN, measure what
272 		 * we have in the current buffer, and continue measuring the remaining
273 		 * targets by prefixing the device metadata again.
274 		 */
275 		if (unlikely(cur_total_buf_len >= DM_IMA_MEASUREMENT_BUF_LEN)) {
276 			dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
277 			r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
278 			if (r < 0)
279 				goto error;
280 
281 			memset(ima_buf, 0, DM_IMA_MEASUREMENT_BUF_LEN);
282 			l = 0;
283 
284 			/*
285 			 * Each new "dm_table_load" entry in IMA log should have device data
286 			 * prefix, so that multiple records from the same "dm_table_load" for
287 			 * a given device can be linked together.
288 			 */
289 			memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
290 			l += table->md->ima.dm_version_str_len;
291 
292 			memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
293 			l += device_data_buf_len;
294 
295 			/*
296 			 * If this iteration of the for loop turns out to be the last target
297 			 * in the table, dm_ima_measure_data("dm_table_load", ...) doesn't need
298 			 * to be called again, just the hash needs to be finalized.
299 			 * "last_target_measured" tracks this state.
300 			 */
301 			last_target_measured = 1;
302 		}
303 
304 		/*
305 		 * Fill-in all the target metadata, so that multiple targets for the same
306 		 * device can be linked together.
307 		 */
308 		memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len);
309 		l += target_metadata_buf_len;
310 
311 		memcpy(ima_buf + l, target_data_buf, target_data_buf_len);
312 		l += target_data_buf_len;
313 	}
314 
315 	if (!last_target_measured) {
316 		dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
317 
318 		r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
319 		if (r < 0)
320 			goto error;
321 	}
322 
323 	/*
324 	 * Finalize the table hash, and store it in table->md->ima.inactive_table.hash,
325 	 * so that the table data can be verified against the future device state change
326 	 * events, e.g. resume, rename, remove, table-clear etc.
327 	 */
328 	r = crypto_shash_final(shash, digest);
329 	if (r < 0)
330 		goto error;
331 
332 	digest_buf = dm_ima_alloc((digest_size*2) + hash_alg_prefix_len + 1, GFP_KERNEL, noio);
333 
334 	if (!digest_buf)
335 		goto error;
336 
337 	snprintf(digest_buf, hash_alg_prefix_len + 1, "%s:", DM_IMA_TABLE_HASH_ALG);
338 
339 	for (i = 0; i < digest_size; i++)
340 		snprintf((digest_buf + hash_alg_prefix_len + (i*2)), 3, "%02x", digest[i]);
341 
342 	if (table->md->ima.active_table.hash != table->md->ima.inactive_table.hash)
343 		kfree(table->md->ima.inactive_table.hash);
344 
345 	table->md->ima.inactive_table.hash = digest_buf;
346 	table->md->ima.inactive_table.hash_len = strlen(digest_buf);
347 	table->md->ima.inactive_table.num_targets = num_targets;
348 
349 	if (table->md->ima.active_table.device_metadata !=
350 	    table->md->ima.inactive_table.device_metadata)
351 		kfree(table->md->ima.inactive_table.device_metadata);
352 
353 	table->md->ima.inactive_table.device_metadata = device_data_buf;
354 	table->md->ima.inactive_table.device_metadata_len = device_data_buf_len;
355 
356 	goto exit;
357 error:
358 	kfree(digest_buf);
359 	kfree(device_data_buf);
360 exit:
361 	kfree(digest);
362 	if (tfm)
363 		crypto_free_shash(tfm);
364 	kfree(ima_buf);
365 	kfree(target_metadata_buf);
366 	kfree(target_data_buf);
367 }
368 
369 /*
370  * Measure IMA data on device resume.
371  */
372 void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap)
373 {
374 	char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
375 	char active[] = "active_table_hash=";
376 	unsigned int active_len = strlen(active), capacity_len = 0;
377 	unsigned int l = 0;
378 	bool noio = true;
379 	bool nodata = true;
380 	int r;
381 
382 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
383 	if (!device_table_data)
384 		return;
385 
386 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
387 	if (r)
388 		goto error;
389 
390 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
391 	l += md->ima.dm_version_str_len;
392 
393 	if (swap) {
394 		if (md->ima.active_table.hash != md->ima.inactive_table.hash)
395 			kfree(md->ima.active_table.hash);
396 
397 		md->ima.active_table.hash = NULL;
398 		md->ima.active_table.hash_len = 0;
399 
400 		if (md->ima.active_table.device_metadata !=
401 		    md->ima.inactive_table.device_metadata)
402 			kfree(md->ima.active_table.device_metadata);
403 
404 		md->ima.active_table.device_metadata = NULL;
405 		md->ima.active_table.device_metadata_len = 0;
406 		md->ima.active_table.num_targets = 0;
407 
408 		if (md->ima.inactive_table.hash) {
409 			md->ima.active_table.hash = md->ima.inactive_table.hash;
410 			md->ima.active_table.hash_len = md->ima.inactive_table.hash_len;
411 			md->ima.inactive_table.hash = NULL;
412 			md->ima.inactive_table.hash_len = 0;
413 		}
414 
415 		if (md->ima.inactive_table.device_metadata) {
416 			md->ima.active_table.device_metadata =
417 				md->ima.inactive_table.device_metadata;
418 			md->ima.active_table.device_metadata_len =
419 				md->ima.inactive_table.device_metadata_len;
420 			md->ima.active_table.num_targets = md->ima.inactive_table.num_targets;
421 			md->ima.inactive_table.device_metadata = NULL;
422 			md->ima.inactive_table.device_metadata_len = 0;
423 			md->ima.inactive_table.num_targets = 0;
424 		}
425 	}
426 
427 	if (md->ima.active_table.device_metadata) {
428 		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
429 		       md->ima.active_table.device_metadata_len);
430 		l += md->ima.active_table.device_metadata_len;
431 
432 		nodata = false;
433 	}
434 
435 	if (md->ima.active_table.hash) {
436 		memcpy(device_table_data + l, active, active_len);
437 		l += active_len;
438 
439 		memcpy(device_table_data + l, md->ima.active_table.hash,
440 		       md->ima.active_table.hash_len);
441 		l += md->ima.active_table.hash_len;
442 
443 		memcpy(device_table_data + l, ";", 1);
444 		l++;
445 
446 		nodata = false;
447 	}
448 
449 	if (nodata) {
450 		r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
451 		if (r)
452 			goto error;
453 
454 		scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
455 			  "%sname=%s,uuid=%s;device_resume=no_data;",
456 			  DM_IMA_VERSION_STR, dev_name, dev_uuid);
457 		l += strlen(device_table_data);
458 
459 	}
460 
461 	capacity_len = strlen(capacity_str);
462 	memcpy(device_table_data + l, capacity_str, capacity_len);
463 	l += capacity_len;
464 
465 	dm_ima_measure_data("dm_device_resume", device_table_data, l, noio);
466 
467 	kfree(dev_name);
468 	kfree(dev_uuid);
469 error:
470 	kfree(capacity_str);
471 	kfree(device_table_data);
472 }
473 
474 /*
475  * Measure IMA data on remove.
476  */
477 void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
478 {
479 	char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
480 	char active_table_str[] = "active_table_hash=";
481 	char inactive_table_str[] = "inactive_table_hash=";
482 	char device_active_str[] = "device_active_metadata=";
483 	char device_inactive_str[] = "device_inactive_metadata=";
484 	char remove_all_str[] = "remove_all=";
485 	unsigned int active_table_len = strlen(active_table_str);
486 	unsigned int inactive_table_len = strlen(inactive_table_str);
487 	unsigned int device_active_len = strlen(device_active_str);
488 	unsigned int device_inactive_len = strlen(device_inactive_str);
489 	unsigned int remove_all_len = strlen(remove_all_str);
490 	unsigned int capacity_len = 0;
491 	unsigned int l = 0;
492 	bool noio = true;
493 	bool nodata = true;
494 	int r;
495 
496 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, GFP_KERNEL, noio);
497 	if (!device_table_data)
498 		goto exit;
499 
500 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
501 	if (r) {
502 		kfree(device_table_data);
503 		goto exit;
504 	}
505 
506 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
507 	l += md->ima.dm_version_str_len;
508 
509 	if (md->ima.active_table.device_metadata) {
510 		memcpy(device_table_data + l, device_active_str, device_active_len);
511 		l += device_active_len;
512 
513 		memcpy(device_table_data + l, md->ima.active_table.device_metadata,
514 		       md->ima.active_table.device_metadata_len);
515 		l += md->ima.active_table.device_metadata_len;
516 
517 		nodata = false;
518 	}
519 
520 	if (md->ima.inactive_table.device_metadata) {
521 		memcpy(device_table_data + l, device_inactive_str, device_inactive_len);
522 		l += device_inactive_len;
523 
524 		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
525 		       md->ima.inactive_table.device_metadata_len);
526 		l += md->ima.inactive_table.device_metadata_len;
527 
528 		nodata = false;
529 	}
530 
531 	if (md->ima.active_table.hash) {
532 		memcpy(device_table_data + l, active_table_str, active_table_len);
533 		l += active_table_len;
534 
535 		memcpy(device_table_data + l, md->ima.active_table.hash,
536 			   md->ima.active_table.hash_len);
537 		l += md->ima.active_table.hash_len;
538 
539 		memcpy(device_table_data + l, ",", 1);
540 		l++;
541 
542 		nodata = false;
543 	}
544 
545 	if (md->ima.inactive_table.hash) {
546 		memcpy(device_table_data + l, inactive_table_str, inactive_table_len);
547 		l += inactive_table_len;
548 
549 		memcpy(device_table_data + l, md->ima.inactive_table.hash,
550 		       md->ima.inactive_table.hash_len);
551 		l += md->ima.inactive_table.hash_len;
552 
553 		memcpy(device_table_data + l, ",", 1);
554 		l++;
555 
556 		nodata = false;
557 	}
558 	/*
559 	 * In case both active and inactive tables, and corresponding
560 	 * device metadata is cleared/missing - record the name and uuid
561 	 * in IMA measurements.
562 	 */
563 	if (nodata) {
564 		if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
565 			goto error;
566 
567 		scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
568 			  "%sname=%s,uuid=%s;device_remove=no_data;",
569 			  DM_IMA_VERSION_STR, dev_name, dev_uuid);
570 		l += strlen(device_table_data);
571 	}
572 
573 	memcpy(device_table_data + l, remove_all_str, remove_all_len);
574 	l += remove_all_len;
575 	memcpy(device_table_data + l, remove_all ? "y;" : "n;", 2);
576 	l += 2;
577 
578 	capacity_len = strlen(capacity_str);
579 	memcpy(device_table_data + l, capacity_str, capacity_len);
580 	l += capacity_len;
581 
582 	dm_ima_measure_data("dm_device_remove", device_table_data, l, noio);
583 
584 error:
585 	kfree(device_table_data);
586 	kfree(capacity_str);
587 exit:
588 	kfree(md->ima.active_table.device_metadata);
589 
590 	if (md->ima.active_table.device_metadata !=
591 	    md->ima.inactive_table.device_metadata)
592 		kfree(md->ima.inactive_table.device_metadata);
593 
594 	kfree(md->ima.active_table.hash);
595 
596 	if (md->ima.active_table.hash != md->ima.inactive_table.hash)
597 		kfree(md->ima.inactive_table.hash);
598 
599 	dm_ima_reset_data(md);
600 
601 	kfree(dev_name);
602 	kfree(dev_uuid);
603 }
604 
605 /*
606  * Measure ima data on table clear.
607  */
608 void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
609 {
610 	unsigned int l = 0, capacity_len = 0;
611 	char *device_table_data = NULL, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
612 	char inactive_str[] = "inactive_table_hash=";
613 	unsigned int inactive_len = strlen(inactive_str);
614 	bool noio = true;
615 	bool nodata = true;
616 	int r;
617 
618 	device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
619 	if (!device_table_data)
620 		return;
621 
622 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
623 	if (r)
624 		goto error1;
625 
626 	memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
627 	l += md->ima.dm_version_str_len;
628 
629 	if (md->ima.inactive_table.device_metadata_len &&
630 	    md->ima.inactive_table.hash_len) {
631 		memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
632 		       md->ima.inactive_table.device_metadata_len);
633 		l += md->ima.inactive_table.device_metadata_len;
634 
635 		memcpy(device_table_data + l, inactive_str, inactive_len);
636 		l += inactive_len;
637 
638 		memcpy(device_table_data + l, md->ima.inactive_table.hash,
639 			   md->ima.inactive_table.hash_len);
640 
641 		l += md->ima.inactive_table.hash_len;
642 
643 		memcpy(device_table_data + l, ";", 1);
644 		l++;
645 
646 		nodata = false;
647 	}
648 
649 	if (nodata) {
650 		if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
651 			goto error2;
652 
653 		scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
654 			  "%sname=%s,uuid=%s;table_clear=no_data;",
655 			   DM_IMA_VERSION_STR, dev_name, dev_uuid);
656 		l += strlen(device_table_data);
657 	}
658 
659 	capacity_len = strlen(capacity_str);
660 	memcpy(device_table_data + l, capacity_str, capacity_len);
661 	l += capacity_len;
662 
663 	dm_ima_measure_data("dm_table_clear", device_table_data, l, noio);
664 
665 	if (new_map) {
666 		if (md->ima.inactive_table.hash &&
667 		    md->ima.inactive_table.hash != md->ima.active_table.hash)
668 			kfree(md->ima.inactive_table.hash);
669 
670 		md->ima.inactive_table.hash = NULL;
671 		md->ima.inactive_table.hash_len = 0;
672 
673 		if (md->ima.inactive_table.device_metadata &&
674 		    md->ima.inactive_table.device_metadata != md->ima.active_table.device_metadata)
675 			kfree(md->ima.inactive_table.device_metadata);
676 
677 		md->ima.inactive_table.device_metadata = NULL;
678 		md->ima.inactive_table.device_metadata_len = 0;
679 		md->ima.inactive_table.num_targets = 0;
680 
681 		if (md->ima.active_table.hash) {
682 			md->ima.inactive_table.hash = md->ima.active_table.hash;
683 			md->ima.inactive_table.hash_len = md->ima.active_table.hash_len;
684 		}
685 
686 		if (md->ima.active_table.device_metadata) {
687 			md->ima.inactive_table.device_metadata =
688 				md->ima.active_table.device_metadata;
689 			md->ima.inactive_table.device_metadata_len =
690 				md->ima.active_table.device_metadata_len;
691 			md->ima.inactive_table.num_targets =
692 				md->ima.active_table.num_targets;
693 		}
694 	}
695 
696 	kfree(dev_name);
697 	kfree(dev_uuid);
698 error2:
699 	kfree(capacity_str);
700 error1:
701 	kfree(device_table_data);
702 }
703 
704 /*
705  * Measure IMA data on device rename.
706  */
707 void dm_ima_measure_on_device_rename(struct mapped_device *md)
708 {
709 	char *old_device_data = NULL, *new_device_data = NULL, *combined_device_data = NULL;
710 	char *new_dev_name = NULL, *new_dev_uuid = NULL, *capacity_str = NULL;
711 	bool noio = true;
712 	int r;
713 
714 	if (dm_ima_alloc_and_copy_device_data(md, &new_device_data,
715 					      md->ima.active_table.num_targets, noio))
716 		return;
717 
718 	if (dm_ima_alloc_and_copy_name_uuid(md, &new_dev_name, &new_dev_uuid, noio))
719 		goto error;
720 
721 	combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, GFP_KERNEL, noio);
722 	if (!combined_device_data)
723 		goto error;
724 
725 	r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
726 	if (r)
727 		goto error;
728 
729 	old_device_data = md->ima.active_table.device_metadata;
730 
731 	md->ima.active_table.device_metadata = new_device_data;
732 	md->ima.active_table.device_metadata_len = strlen(new_device_data);
733 
734 	scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2,
735 		  "%s%snew_name=%s,new_uuid=%s;%s", DM_IMA_VERSION_STR, old_device_data,
736 		  new_dev_name, new_dev_uuid, capacity_str);
737 
738 	dm_ima_measure_data("dm_device_rename", combined_device_data, strlen(combined_device_data),
739 			    noio);
740 
741 	goto exit;
742 
743 error:
744 	kfree(new_device_data);
745 exit:
746 	kfree(capacity_str);
747 	kfree(combined_device_data);
748 	kfree(old_device_data);
749 	kfree(new_dev_name);
750 	kfree(new_dev_uuid);
751 }
752