drivers/md/dm-ima.c

   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 }