drivers/md/dm-ima.c

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