1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Integrity Measurement Architecture 4 * 5 * Copyright (C) 2005,2006,2007,2008 IBM Corporation 6 * 7 * Authors: 8 * Reiner Sailer <sailer@watson.ibm.com> 9 * Serge Hallyn <serue@us.ibm.com> 10 * Kylene Hall <kylene@us.ibm.com> 11 * Mimi Zohar <zohar@us.ibm.com> 12 * 13 * File: ima_main.c 14 * implements the IMA hooks: ima_bprm_check, ima_file_mmap, 15 * and ima_file_check. 16 */ 17 18 #include <linux/module.h> 19 #include <linux/file.h> 20 #include <linux/binfmts.h> 21 #include <linux/kernel_read_file.h> 22 #include <linux/mount.h> 23 #include <linux/mman.h> 24 #include <linux/slab.h> 25 #include <linux/xattr.h> 26 #include <linux/ima.h> 27 #include <linux/fs.h> 28 #include <linux/iversion.h> 29 #include <linux/evm.h> 30 #include <linux/crash_dump.h> 31 32 #include "ima.h" 33 34 #ifdef CONFIG_IMA_APPRAISE 35 int ima_appraise = IMA_APPRAISE_ENFORCE; 36 #else 37 int ima_appraise; 38 #endif 39 40 int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1; 41 static int hash_setup_done; 42 static int ima_disabled __ro_after_init; 43 44 static struct notifier_block ima_lsm_policy_notifier = { 45 .notifier_call = ima_lsm_policy_change, 46 }; 47 48 static int __init ima_setup(char *str) 49 { 50 if (!is_kdump_kernel()) { 51 pr_info("Warning: ima setup option only permitted in kdump"); 52 return 1; 53 } 54 55 if (strncmp(str, "off", 3) == 0) 56 ima_disabled = 1; 57 else if (strncmp(str, "on", 2) == 0) 58 ima_disabled = 0; 59 else 60 pr_err("Invalid ima setup option: \"%s\" , please specify ima=on|off.", str); 61 62 return 1; 63 } 64 __setup("ima=", ima_setup); 65 66 static int __init hash_setup(char *str) 67 { 68 struct ima_template_desc *template_desc = ima_template_desc_current(); 69 int i; 70 71 if (hash_setup_done) 72 return 1; 73 74 if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) { 75 if (strncmp(str, "sha1", 4) == 0) { 76 ima_hash_algo = HASH_ALGO_SHA1; 77 } else if (strncmp(str, "md5", 3) == 0) { 78 ima_hash_algo = HASH_ALGO_MD5; 79 } else { 80 pr_err("invalid hash algorithm \"%s\" for template \"%s\"", 81 str, IMA_TEMPLATE_IMA_NAME); 82 return 1; 83 } 84 goto out; 85 } 86 87 i = match_string(hash_algo_name, HASH_ALGO__LAST, str); 88 if (i < 0) { 89 pr_err("invalid hash algorithm \"%s\"", str); 90 return 1; 91 } 92 93 ima_hash_algo = i; 94 out: 95 hash_setup_done = 1; 96 return 1; 97 } 98 __setup("ima_hash=", hash_setup); 99 100 enum hash_algo ima_get_current_hash_algo(void) 101 { 102 return ima_hash_algo; 103 } 104 105 /* Prevent mmap'ing a file execute that is already mmap'ed write */ 106 static int mmap_violation_check(enum ima_hooks func, struct file *file, 107 char **pathbuf, const char **pathname, 108 char *filename) 109 { 110 struct inode *inode; 111 int rc = 0; 112 113 if ((func == MMAP_CHECK || func == MMAP_CHECK_REQPROT) && 114 mapping_writably_mapped(file->f_mapping)) { 115 rc = -ETXTBSY; 116 inode = file_inode(file); 117 118 if (!*pathbuf) /* ima_rdwr_violation possibly pre-fetched */ 119 *pathname = ima_d_path(&file->f_path, pathbuf, 120 filename); 121 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname, 122 "mmap_file", "mmapped_writers", rc, 0); 123 } 124 return rc; 125 } 126 127 /* 128 * ima_rdwr_violation_check 129 * 130 * Only invalidate the PCR for measured files: 131 * - Opening a file for write when already open for read, 132 * results in a time of measure, time of use (ToMToU) error. 133 * - Opening a file for read when already open for write, 134 * could result in a file measurement error. 135 * 136 */ 137 static void ima_rdwr_violation_check(struct file *file, 138 struct ima_iint_cache *iint, 139 int must_measure, 140 char **pathbuf, 141 const char **pathname, 142 char *filename) 143 { 144 struct inode *inode = file_inode(file); 145 fmode_t mode = file->f_mode; 146 bool send_tomtou = false, send_writers = false; 147 148 if (mode & FMODE_WRITE) { 149 if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { 150 if (!iint) 151 iint = ima_iint_find(inode); 152 153 /* IMA_MEASURE is set from reader side */ 154 if (iint && test_and_clear_bit(IMA_MAY_EMIT_TOMTOU, 155 &iint->atomic_flags)) 156 send_tomtou = true; 157 } 158 } else { 159 if (must_measure) 160 set_bit(IMA_MAY_EMIT_TOMTOU, &iint->atomic_flags); 161 162 /* Limit number of open_writers violations */ 163 if (inode_is_open_for_write(inode) && must_measure) { 164 if (!test_and_set_bit(IMA_EMITTED_OPENWRITERS, 165 &iint->atomic_flags)) 166 send_writers = true; 167 } 168 } 169 170 if (!send_tomtou && !send_writers) 171 return; 172 173 *pathname = ima_d_path(&file->f_path, pathbuf, filename); 174 175 if (send_tomtou) 176 ima_add_violation(file, *pathname, iint, 177 "invalid_pcr", "ToMToU"); 178 if (send_writers) 179 ima_add_violation(file, *pathname, iint, 180 "invalid_pcr", "open_writers"); 181 } 182 183 /* 184 * Detect file change based on STATX_CHANGE_COOKIE, when supported, and 185 * fallback to detecting file change based on i_version. On filesystems 186 * which do not support either, assume the file changed. 187 */ 188 static bool ima_detect_file_change(struct ima_iint_cache *iint, 189 struct inode *inode, struct file *file) 190 { 191 struct kstat stat; 192 int result; 193 194 result = vfs_getattr_nosec(&file->f_path, &stat, STATX_CHANGE_COOKIE, 195 AT_STATX_SYNC_AS_STAT); 196 197 if (!result && stat.result_mask & STATX_CHANGE_COOKIE) 198 return stat.change_cookie != iint->real_inode.version; 199 200 if (IS_I_VERSION(inode)) 201 return !inode_eq_iversion(inode, iint->real_inode.version); 202 203 return true; 204 } 205 206 static void ima_check_last_writer(struct ima_iint_cache *iint, 207 struct inode *inode, struct file *file) 208 { 209 fmode_t mode = file->f_mode; 210 bool update; 211 212 if (!(mode & FMODE_WRITE)) 213 return; 214 215 mutex_lock(&iint->mutex); 216 if (atomic_read(&inode->i_writecount) == 1) { 217 clear_bit(IMA_EMITTED_OPENWRITERS, &iint->atomic_flags); 218 219 update = test_and_clear_bit(IMA_UPDATE_XATTR, 220 &iint->atomic_flags); 221 222 if (iint->flags & IMA_NEW_FILE || 223 ima_detect_file_change(iint, inode, file)) { 224 iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); 225 iint->measured_pcrs = 0; 226 if (update) 227 ima_update_xattr(iint, file); 228 } 229 } 230 mutex_unlock(&iint->mutex); 231 } 232 233 /** 234 * ima_file_free - called on __fput() 235 * @file: pointer to file structure being freed 236 * 237 * Flag files that changed, based on i_version 238 */ 239 static void ima_file_free(struct file *file) 240 { 241 struct inode *inode = file_inode(file); 242 struct ima_iint_cache *iint; 243 244 if (!ima_policy_flag || !S_ISREG(inode->i_mode)) 245 return; 246 247 iint = ima_iint_find(inode); 248 if (!iint) 249 return; 250 251 ima_check_last_writer(iint, inode, file); 252 } 253 254 static int process_measurement(struct file *file, const struct cred *cred, 255 struct lsm_prop *prop, char *buf, loff_t size, 256 int mask, enum ima_hooks func, 257 enum kernel_read_file_id read_id, 258 bool bprm_is_check) 259 { 260 struct inode *real_inode, *inode = file_inode(file); 261 struct ima_iint_cache *iint = NULL; 262 struct ima_template_desc *template_desc = NULL; 263 struct inode *metadata_inode; 264 char *pathbuf = NULL; 265 char filename[NAME_MAX]; 266 const char *pathname = NULL; 267 int rc = 0, action, must_appraise = 0; 268 int pcr = CONFIG_IMA_MEASURE_PCR_IDX; 269 struct evm_ima_xattr_data *xattr_value = NULL; 270 struct modsig *modsig = NULL; 271 int xattr_len = 0; 272 bool violation_check; 273 enum hash_algo hash_algo; 274 unsigned int allowed_algos = 0; 275 276 if (!ima_policy_flag || !S_ISREG(inode->i_mode)) 277 return 0; 278 279 /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action 280 * bitmask based on the appraise/audit/measurement policy. 281 * Included is the appraise submask. 282 */ 283 action = ima_get_action(file_mnt_idmap(file), inode, cred, prop, 284 mask, func, &pcr, &template_desc, NULL, 285 &allowed_algos); 286 violation_check = ((func == FILE_CHECK || func == MMAP_CHECK || 287 func == MMAP_CHECK_REQPROT) && 288 (ima_policy_flag & IMA_MEASURE) && 289 ((action & IMA_MEASURE) || 290 (file->f_mode & FMODE_WRITE))); 291 if (!action && !violation_check) 292 return 0; 293 294 must_appraise = action & IMA_APPRAISE; 295 296 /* Is the appraise rule hook specific? */ 297 if (action & IMA_FILE_APPRAISE) 298 func = FILE_CHECK; 299 300 inode_lock(inode); 301 302 if (action) { 303 iint = ima_inode_get(inode); 304 if (!iint) 305 rc = -ENOMEM; 306 } 307 308 if (!rc && violation_check) 309 ima_rdwr_violation_check(file, iint, action & IMA_MEASURE, 310 &pathbuf, &pathname, filename); 311 312 inode_unlock(inode); 313 314 if (rc) 315 goto out; 316 if (!action) 317 goto out; 318 319 mutex_lock(&iint->mutex); 320 321 if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags)) 322 /* 323 * Reset appraisal flags (action and non-action rule-specific) 324 * if ima_inode_post_setattr was called. 325 */ 326 iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | 327 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | 328 IMA_NONACTION_RULE_FLAGS); 329 330 /* 331 * Re-evaulate the file if either the xattr has changed or the 332 * kernel has no way of detecting file change on the filesystem. 333 * (Limited to privileged mounted filesystems.) 334 */ 335 if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) || 336 ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) && 337 !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) && 338 !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) { 339 iint->flags &= ~IMA_DONE_MASK; 340 iint->measured_pcrs = 0; 341 } 342 343 /* 344 * On stacked filesystems, detect and re-evaluate file data and 345 * metadata changes. 346 */ 347 real_inode = d_real_inode(file_dentry(file)); 348 if (real_inode != inode && 349 (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) { 350 if (!IS_I_VERSION(real_inode) || 351 integrity_inode_attrs_changed(&iint->real_inode, 352 real_inode)) { 353 iint->flags &= ~IMA_DONE_MASK; 354 iint->measured_pcrs = 0; 355 } 356 357 /* 358 * Reset the EVM status when metadata changed. 359 */ 360 metadata_inode = d_inode(d_real(file_dentry(file), 361 D_REAL_METADATA)); 362 if (evm_metadata_changed(inode, metadata_inode)) 363 iint->flags &= ~(IMA_APPRAISED | 364 IMA_APPRAISED_SUBMASK); 365 } 366 367 /* Determine if already appraised/measured based on bitmask 368 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED, 369 * IMA_AUDIT, IMA_AUDITED) 370 */ 371 iint->flags |= action; 372 action &= IMA_DO_MASK; 373 action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1); 374 375 /* If target pcr is already measured, unset IMA_MEASURE action */ 376 if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr))) 377 action ^= IMA_MEASURE; 378 379 /* HASH sets the digital signature and update flags, nothing else */ 380 if ((action & IMA_HASH) && 381 !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) { 382 xattr_len = ima_read_xattr(file_dentry(file), 383 &xattr_value, xattr_len); 384 if ((xattr_value && xattr_len > 2) && 385 (xattr_value->type == EVM_IMA_XATTR_DIGSIG)) 386 set_bit(IMA_DIGSIG, &iint->atomic_flags); 387 iint->flags |= IMA_HASHED; 388 action ^= IMA_HASH; 389 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); 390 } 391 392 /* Nothing to do, just return existing appraised status */ 393 if (!action) { 394 if (must_appraise) { 395 rc = mmap_violation_check(func, file, &pathbuf, 396 &pathname, filename); 397 if (!rc) 398 rc = ima_get_cache_status(iint, func); 399 } 400 goto out_locked; 401 } 402 403 if ((action & IMA_APPRAISE_SUBMASK) || 404 strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) { 405 /* read 'security.ima' */ 406 xattr_len = ima_read_xattr(file_dentry(file), 407 &xattr_value, xattr_len); 408 409 /* 410 * Read the appended modsig if allowed by the policy, and allow 411 * an additional measurement list entry, if needed, based on the 412 * template format and whether the file was already measured. 413 */ 414 if (iint->flags & IMA_MODSIG_ALLOWED) { 415 rc = ima_read_modsig(func, buf, size, &modsig); 416 417 if (!rc && ima_template_has_modsig(template_desc) && 418 iint->flags & IMA_MEASURED) 419 action |= IMA_MEASURE; 420 } 421 } 422 423 hash_algo = ima_get_hash_algo(xattr_value, xattr_len); 424 425 rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig); 426 if (rc != 0 && rc != -EBADF && rc != -EINVAL) 427 goto out_locked; 428 429 /* Defer measuring/appraising kernel modules to READING_MODULE */ 430 if (read_id == READING_MODULE_COMPRESSED) { 431 must_appraise = 0; 432 goto out_locked; 433 } 434 435 if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */ 436 pathname = ima_d_path(&file->f_path, &pathbuf, filename); 437 438 if (action & IMA_MEASURE) 439 ima_store_measurement(iint, file, pathname, 440 xattr_value, xattr_len, modsig, pcr, 441 template_desc); 442 if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) { 443 rc = ima_check_blacklist(iint, modsig, pcr); 444 if (rc != -EPERM) { 445 inode_lock(inode); 446 rc = ima_appraise_measurement(func, iint, file, 447 pathname, xattr_value, 448 xattr_len, modsig, 449 bprm_is_check); 450 inode_unlock(inode); 451 } 452 if (!rc) 453 rc = mmap_violation_check(func, file, &pathbuf, 454 &pathname, filename); 455 } 456 if (action & IMA_AUDIT) 457 ima_audit_measurement(iint, pathname); 458 459 if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO)) 460 rc = 0; 461 462 /* Ensure the digest was generated using an allowed algorithm */ 463 if (rc == 0 && must_appraise && allowed_algos != 0 && 464 (allowed_algos & (1U << hash_algo)) == 0) { 465 rc = -EACCES; 466 467 integrity_audit_msg(AUDIT_INTEGRITY_DATA, file_inode(file), 468 pathname, "collect_data", 469 "denied-hash-algorithm", rc, 0); 470 } 471 out_locked: 472 if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) && 473 !(iint->flags & IMA_NEW_FILE)) 474 rc = -EACCES; 475 mutex_unlock(&iint->mutex); 476 kfree(xattr_value); 477 ima_free_modsig(modsig); 478 out: 479 if (pathbuf) 480 __putname(pathbuf); 481 if (must_appraise) { 482 if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE)) 483 return -EACCES; 484 if (file->f_mode & FMODE_WRITE) 485 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); 486 } 487 return 0; 488 } 489 490 /** 491 * ima_file_mmap - based on policy, collect/store measurement. 492 * @file: pointer to the file to be measured (May be NULL) 493 * @reqprot: protection requested by the application 494 * @prot: protection that will be applied by the kernel 495 * @flags: operational flags 496 * 497 * Measure files being mmapped executable based on the ima_must_measure() 498 * policy decision. 499 * 500 * On success return 0. On integrity appraisal error, assuming the file 501 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 502 */ 503 static int ima_file_mmap(struct file *file, unsigned long reqprot, 504 unsigned long prot, unsigned long flags) 505 { 506 struct lsm_prop prop; 507 int ret; 508 509 if (!file) 510 return 0; 511 512 security_current_getlsmprop_subj(&prop); 513 514 if (reqprot & PROT_EXEC) { 515 ret = process_measurement(file, current_cred(), &prop, NULL, 516 0, MAY_EXEC, MMAP_CHECK_REQPROT, 0, 517 false); 518 if (ret) 519 return ret; 520 } 521 522 if (prot & PROT_EXEC) 523 return process_measurement(file, current_cred(), &prop, NULL, 524 0, MAY_EXEC, MMAP_CHECK, 0, false); 525 526 return 0; 527 } 528 529 /** 530 * ima_file_mprotect - based on policy, limit mprotect change 531 * @vma: vm_area_struct protection is set to 532 * @reqprot: protection requested by the application 533 * @prot: protection that will be applied by the kernel 534 * 535 * Files can be mmap'ed read/write and later changed to execute to circumvent 536 * IMA's mmap appraisal policy rules. Due to locking issues (mmap semaphore 537 * would be taken before i_mutex), files can not be measured or appraised at 538 * this point. Eliminate this integrity gap by denying the mprotect 539 * PROT_EXECUTE change, if an mmap appraise policy rule exists. 540 * 541 * On mprotect change success, return 0. On failure, return -EACESS. 542 */ 543 static int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, 544 unsigned long prot) 545 { 546 struct ima_template_desc *template = NULL; 547 struct file *file; 548 char filename[NAME_MAX]; 549 char *pathbuf = NULL; 550 const char *pathname = NULL; 551 struct inode *inode; 552 struct lsm_prop prop; 553 int result = 0; 554 int action; 555 int pcr; 556 557 /* Is mprotect making an mmap'ed file executable? */ 558 if (!(ima_policy_flag & IMA_APPRAISE) || !vma->vm_file || 559 !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC)) 560 return 0; 561 562 security_current_getlsmprop_subj(&prop); 563 inode = file_inode(vma->vm_file); 564 action = ima_get_action(file_mnt_idmap(vma->vm_file), inode, 565 current_cred(), &prop, MAY_EXEC, MMAP_CHECK, 566 &pcr, &template, NULL, NULL); 567 action |= ima_get_action(file_mnt_idmap(vma->vm_file), inode, 568 current_cred(), &prop, MAY_EXEC, 569 MMAP_CHECK_REQPROT, &pcr, &template, NULL, 570 NULL); 571 572 /* Is the mmap'ed file in policy? */ 573 if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK))) 574 return 0; 575 576 if (action & IMA_APPRAISE_SUBMASK) 577 result = -EPERM; 578 579 file = vma->vm_file; 580 pathname = ima_d_path(&file->f_path, &pathbuf, filename); 581 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, pathname, 582 "collect_data", "failed-mprotect", result, 0); 583 if (pathbuf) 584 __putname(pathbuf); 585 586 return result; 587 } 588 589 /** 590 * ima_bprm_check - based on policy, collect/store measurement. 591 * @bprm: contains the linux_binprm structure 592 * 593 * The OS protects against an executable file, already open for write, 594 * from being executed in deny_write_access() and an executable file, 595 * already open for execute, from being modified in get_write_access(). 596 * So we can be certain that what we verify and measure here is actually 597 * what is being executed. 598 * 599 * On success return 0. On integrity appraisal error, assuming the file 600 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 601 */ 602 static int ima_bprm_check(struct linux_binprm *bprm) 603 { 604 struct lsm_prop prop; 605 606 security_current_getlsmprop_subj(&prop); 607 return process_measurement(bprm->file, current_cred(), 608 &prop, NULL, 0, MAY_EXEC, BPRM_CHECK, 0, 609 bprm->is_check); 610 } 611 612 /** 613 * ima_creds_check - based on policy, collect/store measurement. 614 * @bprm: contains the linux_binprm structure 615 * @file: contains the file descriptor of the binary being executed 616 * 617 * The OS protects against an executable file, already open for write, 618 * from being executed in deny_write_access() and an executable file, 619 * already open for execute, from being modified in get_write_access(). 620 * So we can be certain that what we verify and measure here is actually 621 * what is being executed. 622 * 623 * The difference from ima_bprm_check() is that ima_creds_check() is invoked 624 * only after determining the final binary to be executed without interpreter, 625 * and not when searching for intermediate binaries. The reason is that since 626 * commit 56305aa9b6fab ("exec: Compute file based creds only once"), the 627 * credentials to be applied to the process are calculated only at that stage 628 * (bprm_creds_from_file security hook instead of bprm_check_security). 629 * 630 * On success return 0. On integrity appraisal error, assuming the file 631 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 632 */ 633 static int ima_creds_check(struct linux_binprm *bprm, const struct file *file) 634 { 635 struct lsm_prop prop; 636 637 security_current_getlsmprop_subj(&prop); 638 return process_measurement((struct file *)file, bprm->cred, &prop, NULL, 639 0, MAY_EXEC, CREDS_CHECK, 0, false); 640 } 641 642 /** 643 * ima_bprm_creds_for_exec - collect/store/appraise measurement. 644 * @bprm: contains the linux_binprm structure 645 * 646 * Based on the IMA policy and the execveat(2) AT_EXECVE_CHECK flag, measure 647 * and appraise the integrity of a file to be executed by script interpreters. 648 * Unlike any of the other LSM hooks where the kernel enforces file integrity, 649 * enforcing file integrity is left up to the discretion of the script 650 * interpreter (userspace). 651 * 652 * On success return 0. On integrity appraisal error, assuming the file 653 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 654 */ 655 static int ima_bprm_creds_for_exec(struct linux_binprm *bprm) 656 { 657 /* 658 * As security_bprm_check() is called multiple times, both 659 * the script and the shebang interpreter are measured, appraised, 660 * and audited. Limit usage of this LSM hook to just measuring, 661 * appraising, and auditing the indirect script execution 662 * (e.g. ./sh example.sh). 663 */ 664 if (!bprm->is_check) 665 return 0; 666 667 return ima_bprm_check(bprm); 668 } 669 670 /** 671 * ima_file_check - based on policy, collect/store measurement. 672 * @file: pointer to the file to be measured 673 * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND 674 * 675 * Measure files based on the ima_must_measure() policy decision. 676 * 677 * On success return 0. On integrity appraisal error, assuming the file 678 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 679 */ 680 static int ima_file_check(struct file *file, int mask) 681 { 682 struct lsm_prop prop; 683 684 security_current_getlsmprop_subj(&prop); 685 return process_measurement(file, current_cred(), &prop, NULL, 0, 686 mask & (MAY_READ | MAY_WRITE | MAY_EXEC | 687 MAY_APPEND), FILE_CHECK, 0, false); 688 } 689 690 /* 691 * ima_reset_action_flags - invalidate action flags after a content change 692 * @inode: inode of the file whose content is about to be truncated 693 * 694 * Clear IMA_DONE_MASK so the file is re-collected, re-measured, 695 * re-audited, and re-appraised on next access. 696 */ 697 static void ima_reset_action_flags(struct inode *inode) 698 { 699 struct ima_iint_cache *iint; 700 701 if (!ima_policy_flag || !S_ISREG(inode->i_mode)) 702 return; 703 704 iint = ima_iint_find(inode); 705 if (!iint) 706 return; 707 708 mutex_lock(&iint->mutex); 709 iint->flags &= ~IMA_DONE_MASK; 710 iint->measured_pcrs = 0; 711 mutex_unlock(&iint->mutex); 712 return; 713 } 714 715 static int ima_path_truncate(const struct path *path) 716 { 717 ima_reset_action_flags(path->dentry->d_inode); 718 return 0; 719 } 720 721 static int ima_file_truncate(struct file *file) 722 { 723 ima_reset_action_flags(file_inode(file)); 724 return 0; 725 } 726 727 static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf, 728 size_t buf_size) 729 { 730 struct ima_iint_cache *iint = NULL, tmp_iint; 731 int rc, hash_algo; 732 733 if (ima_policy_flag) { 734 iint = ima_iint_find(inode); 735 if (iint) 736 mutex_lock(&iint->mutex); 737 } 738 739 if ((!iint || !(iint->flags & IMA_COLLECTED)) && file) { 740 if (iint) 741 mutex_unlock(&iint->mutex); 742 743 memset(&tmp_iint, 0, sizeof(tmp_iint)); 744 mutex_init(&tmp_iint.mutex); 745 746 rc = ima_collect_measurement(&tmp_iint, file, NULL, 0, 747 ima_hash_algo, NULL); 748 if (rc < 0) { 749 /* ima_hash could be allocated in case of failure. */ 750 if (rc != -ENOMEM) 751 kfree(tmp_iint.ima_hash); 752 753 return -EOPNOTSUPP; 754 } 755 756 iint = &tmp_iint; 757 mutex_lock(&iint->mutex); 758 } 759 760 if (!iint) 761 return -EOPNOTSUPP; 762 763 /* 764 * ima_file_hash can be called when ima_collect_measurement has still 765 * not been called, we might not always have a hash. 766 */ 767 if (!iint->ima_hash || !(iint->flags & IMA_COLLECTED)) { 768 mutex_unlock(&iint->mutex); 769 return -EOPNOTSUPP; 770 } 771 772 if (buf) { 773 size_t copied_size; 774 775 copied_size = min_t(size_t, iint->ima_hash->length, buf_size); 776 memcpy(buf, iint->ima_hash->digest, copied_size); 777 } 778 hash_algo = iint->ima_hash->algo; 779 mutex_unlock(&iint->mutex); 780 781 if (iint == &tmp_iint) 782 kfree(iint->ima_hash); 783 784 return hash_algo; 785 } 786 787 /** 788 * ima_file_hash - return a measurement of the file 789 * @file: pointer to the file 790 * @buf: buffer in which to store the hash 791 * @buf_size: length of the buffer 792 * 793 * On success, return the hash algorithm (as defined in the enum hash_algo). 794 * If buf is not NULL, this function also outputs the hash into buf. 795 * If the hash is larger than buf_size, then only buf_size bytes will be copied. 796 * It generally just makes sense to pass a buffer capable of holding the largest 797 * possible hash: IMA_MAX_DIGEST_SIZE. 798 * The file hash returned is based on the entire file, including the appended 799 * signature. 800 * 801 * If the measurement cannot be performed, return -EOPNOTSUPP. 802 * If the parameters are incorrect, return -EINVAL. 803 */ 804 int ima_file_hash(struct file *file, char *buf, size_t buf_size) 805 { 806 if (!file) 807 return -EINVAL; 808 809 return __ima_inode_hash(file_inode(file), file, buf, buf_size); 810 } 811 EXPORT_SYMBOL_GPL(ima_file_hash); 812 813 /** 814 * ima_inode_hash - return the stored measurement if the inode has been hashed 815 * and is in the iint cache. 816 * @inode: pointer to the inode 817 * @buf: buffer in which to store the hash 818 * @buf_size: length of the buffer 819 * 820 * On success, return the hash algorithm (as defined in the enum hash_algo). 821 * If buf is not NULL, this function also outputs the hash into buf. 822 * If the hash is larger than buf_size, then only buf_size bytes will be copied. 823 * It generally just makes sense to pass a buffer capable of holding the largest 824 * possible hash: IMA_MAX_DIGEST_SIZE. 825 * The hash returned is based on the entire contents, including the appended 826 * signature. 827 * 828 * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP. 829 * If the parameters are incorrect, return -EINVAL. 830 */ 831 int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size) 832 { 833 if (!inode) 834 return -EINVAL; 835 836 return __ima_inode_hash(inode, NULL, buf, buf_size); 837 } 838 EXPORT_SYMBOL_GPL(ima_inode_hash); 839 840 /** 841 * ima_post_create_tmpfile - mark newly created tmpfile as new 842 * @idmap: idmap of the mount the inode was found from 843 * @inode: inode of the newly created tmpfile 844 * 845 * No measuring, appraising or auditing of newly created tmpfiles is needed. 846 * Skip calling process_measurement(), but indicate which newly, created 847 * tmpfiles are in policy. 848 */ 849 static void ima_post_create_tmpfile(struct mnt_idmap *idmap, 850 struct inode *inode) 851 852 { 853 struct ima_iint_cache *iint; 854 int must_appraise; 855 856 if (!ima_policy_flag || !S_ISREG(inode->i_mode)) 857 return; 858 859 must_appraise = ima_must_appraise(idmap, inode, MAY_ACCESS, 860 FILE_CHECK); 861 if (!must_appraise) 862 return; 863 864 /* Nothing to do if we can't allocate memory */ 865 iint = ima_inode_get(inode); 866 if (!iint) 867 return; 868 869 /* needed for writing the security xattrs */ 870 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); 871 iint->ima_file_status = INTEGRITY_PASS; 872 } 873 874 /** 875 * ima_post_path_mknod - mark as a new inode 876 * @idmap: idmap of the mount the inode was found from 877 * @dentry: newly created dentry 878 * 879 * Mark files created via the mknodat syscall as new, so that the 880 * file data can be written later. 881 */ 882 static void ima_post_path_mknod(struct mnt_idmap *idmap, struct dentry *dentry) 883 { 884 struct ima_iint_cache *iint; 885 struct inode *inode = dentry->d_inode; 886 int must_appraise; 887 888 if (!ima_policy_flag || !S_ISREG(inode->i_mode)) 889 return; 890 891 must_appraise = ima_must_appraise(idmap, inode, MAY_ACCESS, 892 FILE_CHECK); 893 if (!must_appraise) 894 return; 895 896 /* Nothing to do if we can't allocate memory */ 897 iint = ima_inode_get(inode); 898 if (!iint) 899 return; 900 901 /* needed for re-opening empty files */ 902 iint->flags |= IMA_NEW_FILE; 903 } 904 905 /** 906 * ima_read_file - pre-measure/appraise hook decision based on policy 907 * @file: pointer to the file to be measured/appraised/audit 908 * @read_id: caller identifier 909 * @contents: whether a subsequent call will be made to ima_post_read_file() 910 * 911 * Permit reading a file based on policy. The policy rules are written 912 * in terms of the policy identifier. Appraising the integrity of 913 * a file requires a file descriptor. 914 * 915 * For permission return 0, otherwise return -EACCES. 916 */ 917 static int ima_read_file(struct file *file, enum kernel_read_file_id read_id, 918 bool contents) 919 { 920 enum ima_hooks func; 921 struct lsm_prop prop; 922 923 /* 924 * Do devices using pre-allocated memory run the risk of the 925 * firmware being accessible to the device prior to the completion 926 * of IMA's signature verification any more than when using two 927 * buffers? It may be desirable to include the buffer address 928 * in this API and walk all the dma_map_single() mappings to check. 929 */ 930 931 /* 932 * There will be a call made to ima_post_read_file() with 933 * a filled buffer, so we don't need to perform an extra 934 * read early here. 935 */ 936 if (contents) 937 return 0; 938 939 /* Read entire file for all partial reads. */ 940 func = read_idmap[read_id] ?: FILE_CHECK; 941 security_current_getlsmprop_subj(&prop); 942 return process_measurement(file, current_cred(), &prop, NULL, 0, 943 MAY_READ, func, 0, false); 944 } 945 946 const int read_idmap[READING_MAX_ID] = { 947 [READING_FIRMWARE] = FIRMWARE_CHECK, 948 [READING_MODULE] = MODULE_CHECK, 949 [READING_MODULE_COMPRESSED] = MODULE_CHECK, 950 [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK, 951 [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK, 952 [READING_POLICY] = POLICY_CHECK 953 }; 954 955 /** 956 * ima_post_read_file - in memory collect/appraise/audit measurement 957 * @file: pointer to the file to be measured/appraised/audit 958 * @buf: pointer to in memory file contents 959 * @size: size of in memory file contents 960 * @read_id: caller identifier 961 * 962 * Measure/appraise/audit in memory file based on policy. Policy rules 963 * are written in terms of a policy identifier. 964 * 965 * On success return 0. On integrity appraisal error, assuming the file 966 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 967 */ 968 static int ima_post_read_file(struct file *file, char *buf, loff_t size, 969 enum kernel_read_file_id read_id) 970 { 971 enum ima_hooks func; 972 struct lsm_prop prop; 973 974 /* permit signed certs */ 975 if (!file && read_id == READING_X509_CERTIFICATE) 976 return 0; 977 978 if (!file || !buf || size == 0) { /* should never happen */ 979 if (ima_appraise & IMA_APPRAISE_ENFORCE) 980 return -EACCES; 981 return 0; 982 } 983 984 func = read_idmap[read_id] ?: FILE_CHECK; 985 security_current_getlsmprop_subj(&prop); 986 return process_measurement(file, current_cred(), &prop, buf, size, 987 MAY_READ, func, read_id, false); 988 } 989 990 /** 991 * ima_load_data - appraise decision based on policy 992 * @id: kernel load data caller identifier 993 * @contents: whether the full contents will be available in a later 994 * call to ima_post_load_data(). 995 * 996 * Callers of this LSM hook can not measure, appraise, or audit the 997 * data provided by userspace. Enforce policy rules requiring a file 998 * signature (eg. kexec'ed kernel image). 999 * 1000 * For permission return 0, otherwise return -EACCES. 1001 */ 1002 static int ima_load_data(enum kernel_load_data_id id, bool contents) 1003 { 1004 bool ima_enforce, sig_enforce; 1005 1006 ima_enforce = 1007 (ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE; 1008 1009 switch (id) { 1010 case LOADING_KEXEC_IMAGE: 1011 if (IS_ENABLED(CONFIG_KEXEC_SIG) && arch_get_secureboot()) { 1012 pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n"); 1013 return -EACCES; 1014 } 1015 1016 if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) { 1017 pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n"); 1018 return -EACCES; /* INTEGRITY_UNKNOWN */ 1019 } 1020 break; 1021 case LOADING_FIRMWARE: 1022 if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) { 1023 pr_err("Prevent firmware sysfs fallback loading.\n"); 1024 return -EACCES; /* INTEGRITY_UNKNOWN */ 1025 } 1026 break; 1027 case LOADING_MODULE: 1028 sig_enforce = is_module_sig_enforced(); 1029 1030 if (ima_enforce && (!sig_enforce 1031 && (ima_appraise & IMA_APPRAISE_MODULES))) { 1032 pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n"); 1033 return -EACCES; /* INTEGRITY_UNKNOWN */ 1034 } 1035 break; 1036 default: 1037 break; 1038 } 1039 return 0; 1040 } 1041 1042 /** 1043 * ima_post_load_data - appraise decision based on policy 1044 * @buf: pointer to in memory file contents 1045 * @size: size of in memory file contents 1046 * @load_id: kernel load data caller identifier 1047 * @description: @load_id-specific description of contents 1048 * 1049 * Measure/appraise/audit in memory buffer based on policy. Policy rules 1050 * are written in terms of a policy identifier. 1051 * 1052 * On success return 0. On integrity appraisal error, assuming the file 1053 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. 1054 */ 1055 static int ima_post_load_data(char *buf, loff_t size, 1056 enum kernel_load_data_id load_id, 1057 char *description) 1058 { 1059 if (load_id == LOADING_FIRMWARE) { 1060 if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && 1061 (ima_appraise & IMA_APPRAISE_ENFORCE)) { 1062 pr_err("Prevent firmware loading_store.\n"); 1063 return -EACCES; /* INTEGRITY_UNKNOWN */ 1064 } 1065 return 0; 1066 } 1067 1068 /* 1069 * Measure the init_module syscall buffer containing the ELF image. 1070 */ 1071 if (load_id == LOADING_MODULE) 1072 ima_measure_critical_data("modules", "init_module", 1073 buf, size, true, NULL, 0); 1074 1075 return 0; 1076 } 1077 1078 /** 1079 * process_buffer_measurement - Measure the buffer or the buffer data hash 1080 * @idmap: idmap of the mount the inode was found from 1081 * @inode: inode associated with the object being measured (NULL for KEY_CHECK) 1082 * @buf: pointer to the buffer that needs to be added to the log. 1083 * @size: size of buffer(in bytes). 1084 * @eventname: event name to be used for the buffer entry. 1085 * @func: IMA hook 1086 * @pcr: pcr to extend the measurement 1087 * @func_data: func specific data, may be NULL 1088 * @buf_hash: measure buffer data hash 1089 * @digest: buffer digest will be written to 1090 * @digest_len: buffer length 1091 * 1092 * Based on policy, either the buffer data or buffer data hash is measured 1093 * 1094 * Return: 0 if the buffer has been successfully measured, 1 if the digest 1095 * has been written to the passed location but not added to a measurement entry, 1096 * a negative value otherwise. 1097 */ 1098 int process_buffer_measurement(struct mnt_idmap *idmap, 1099 struct inode *inode, const void *buf, int size, 1100 const char *eventname, enum ima_hooks func, 1101 int pcr, const char *func_data, 1102 bool buf_hash, u8 *digest, size_t digest_len) 1103 { 1104 int ret = 0; 1105 const char *audit_cause = "ENOMEM"; 1106 struct ima_template_entry *entry = NULL; 1107 struct ima_iint_cache iint = {}; 1108 struct ima_event_data event_data = {.iint = &iint, 1109 .filename = eventname, 1110 .buf = buf, 1111 .buf_len = size}; 1112 struct ima_template_desc *template; 1113 struct ima_max_digest_data hash; 1114 struct ima_digest_data *hash_hdr = container_of(&hash.hdr, 1115 struct ima_digest_data, hdr); 1116 char digest_hash[IMA_MAX_DIGEST_SIZE]; 1117 int digest_hash_len = hash_digest_size[ima_hash_algo]; 1118 int violation = 0; 1119 int action = 0; 1120 struct lsm_prop prop; 1121 1122 if (digest && digest_len < digest_hash_len) 1123 return -EINVAL; 1124 1125 if (!ima_policy_flag && !digest) 1126 return -ENOENT; 1127 1128 template = ima_template_desc_buf(); 1129 if (!template) { 1130 ret = -EINVAL; 1131 audit_cause = "ima_template_desc_buf"; 1132 goto out; 1133 } 1134 1135 /* 1136 * Both LSM hooks and auxiliary based buffer measurements are 1137 * based on policy. To avoid code duplication, differentiate 1138 * between the LSM hooks and auxiliary buffer measurements, 1139 * retrieving the policy rule information only for the LSM hook 1140 * buffer measurements. 1141 */ 1142 if (func) { 1143 security_current_getlsmprop_subj(&prop); 1144 action = ima_get_action(idmap, inode, current_cred(), 1145 &prop, 0, func, &pcr, &template, 1146 func_data, NULL); 1147 if (!(action & IMA_MEASURE) && !digest) 1148 return -ENOENT; 1149 } 1150 1151 if (!pcr) 1152 pcr = CONFIG_IMA_MEASURE_PCR_IDX; 1153 1154 iint.ima_hash = hash_hdr; 1155 iint.ima_hash->algo = ima_hash_algo; 1156 iint.ima_hash->length = hash_digest_size[ima_hash_algo]; 1157 1158 ret = ima_calc_buffer_hash(buf, size, iint.ima_hash); 1159 if (ret < 0) { 1160 audit_cause = "hashing_error"; 1161 goto out; 1162 } 1163 1164 if (buf_hash) { 1165 memcpy(digest_hash, hash_hdr->digest, digest_hash_len); 1166 1167 ret = ima_calc_buffer_hash(digest_hash, digest_hash_len, 1168 iint.ima_hash); 1169 if (ret < 0) { 1170 audit_cause = "hashing_error"; 1171 goto out; 1172 } 1173 1174 event_data.buf = digest_hash; 1175 event_data.buf_len = digest_hash_len; 1176 } 1177 1178 if (digest) 1179 memcpy(digest, iint.ima_hash->digest, digest_hash_len); 1180 1181 if (!ima_policy_flag || (func && !(action & IMA_MEASURE))) 1182 return 1; 1183 1184 ret = ima_alloc_init_template(&event_data, &entry, template); 1185 if (ret < 0) { 1186 audit_cause = "alloc_entry"; 1187 goto out; 1188 } 1189 1190 ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr); 1191 if (ret < 0) { 1192 audit_cause = "store_entry"; 1193 ima_free_template_entry(entry); 1194 } 1195 1196 out: 1197 if (ret < 0) 1198 integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, eventname, 1199 func_measure_str(func), 1200 audit_cause, ret, 0, ret); 1201 1202 return ret; 1203 } 1204 1205 /** 1206 * ima_kexec_cmdline - measure kexec cmdline boot args 1207 * @kernel_fd: file descriptor of the kexec kernel being loaded 1208 * @buf: pointer to buffer 1209 * @size: size of buffer 1210 * 1211 * Buffers can only be measured, not appraised. 1212 */ 1213 void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) 1214 { 1215 if (!buf || !size) 1216 return; 1217 1218 CLASS(fd, f)(kernel_fd); 1219 if (fd_empty(f)) 1220 return; 1221 1222 process_buffer_measurement(file_mnt_idmap(fd_file(f)), file_inode(fd_file(f)), 1223 buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0, 1224 NULL, false, NULL, 0); 1225 } 1226 1227 /** 1228 * ima_measure_critical_data - measure kernel integrity critical data 1229 * @event_label: unique event label for grouping and limiting critical data 1230 * @event_name: event name for the record in the IMA measurement list 1231 * @buf: pointer to buffer data 1232 * @buf_len: length of buffer data (in bytes) 1233 * @hash: measure buffer data hash 1234 * @digest: buffer digest will be written to 1235 * @digest_len: buffer length 1236 * 1237 * Measure data critical to the integrity of the kernel into the IMA log 1238 * and extend the pcr. Examples of critical data could be various data 1239 * structures, policies, and states stored in kernel memory that can 1240 * impact the integrity of the system. 1241 * 1242 * Return: 0 if the buffer has been successfully measured, 1 if the digest 1243 * has been written to the passed location but not added to a measurement entry, 1244 * a negative value otherwise. 1245 */ 1246 int ima_measure_critical_data(const char *event_label, 1247 const char *event_name, 1248 const void *buf, size_t buf_len, 1249 bool hash, u8 *digest, size_t digest_len) 1250 { 1251 if (!event_name || !event_label || !buf || !buf_len) 1252 return -ENOPARAM; 1253 1254 return process_buffer_measurement(&nop_mnt_idmap, NULL, buf, buf_len, 1255 event_name, CRITICAL_DATA, 0, 1256 event_label, hash, digest, 1257 digest_len); 1258 } 1259 EXPORT_SYMBOL_GPL(ima_measure_critical_data); 1260 1261 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS 1262 1263 /** 1264 * ima_kernel_module_request - Prevent crypto-pkcs1(rsa,*) requests 1265 * @kmod_name: kernel module name 1266 * 1267 * Avoid a verification loop where verifying the signature of the modprobe 1268 * binary requires executing modprobe itself. Since the modprobe iint->mutex 1269 * is already held when the signature verification is performed, a deadlock 1270 * occurs as soon as modprobe is executed within the critical region, since 1271 * the same lock cannot be taken again. 1272 * 1273 * This happens when public_key_verify_signature(), in case of RSA algorithm, 1274 * use alg_name to store internal information in order to construct an 1275 * algorithm on the fly, but crypto_larval_lookup() will try to use alg_name 1276 * in order to load a kernel module with same name. 1277 * 1278 * Since we don't have any real "crypto-pkcs1(rsa,*)" kernel modules, 1279 * we are safe to fail such module request from crypto_larval_lookup(), and 1280 * avoid the verification loop. 1281 * 1282 * Return: Zero if it is safe to load the kernel module, -EINVAL otherwise. 1283 */ 1284 static int ima_kernel_module_request(char *kmod_name) 1285 { 1286 if (strncmp(kmod_name, "crypto-pkcs1(rsa,", 17) == 0) 1287 return -EINVAL; 1288 1289 return 0; 1290 } 1291 1292 #endif /* CONFIG_INTEGRITY_ASYMMETRIC_KEYS */ 1293 1294 static int __init init_ima(void) 1295 { 1296 int error; 1297 1298 /*Note that turning IMA off is intentionally limited to kdump kernel.*/ 1299 if (ima_disabled && is_kdump_kernel()) { 1300 pr_info("IMA functionality is disabled"); 1301 return 0; 1302 } 1303 1304 ima_appraise_parse_cmdline(); 1305 ima_init_template_list(); 1306 hash_setup(CONFIG_IMA_DEFAULT_HASH); 1307 error = ima_init(); 1308 1309 if (error && strcmp(hash_algo_name[ima_hash_algo], 1310 CONFIG_IMA_DEFAULT_HASH) != 0) { 1311 pr_info("Allocating %s failed, going to use default hash algorithm %s\n", 1312 hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH); 1313 hash_setup_done = 0; 1314 hash_setup(CONFIG_IMA_DEFAULT_HASH); 1315 error = ima_init(); 1316 } 1317 1318 if (error) 1319 return error; 1320 1321 error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier); 1322 if (error) 1323 pr_warn("Couldn't register LSM notifier, error %d\n", error); 1324 1325 if (!error) 1326 ima_update_policy_flags(); 1327 1328 return error; 1329 } 1330 1331 static struct security_hook_list ima_hooks[] __ro_after_init = { 1332 LSM_HOOK_INIT(bprm_check_security, ima_bprm_check), 1333 LSM_HOOK_INIT(bprm_creds_for_exec, ima_bprm_creds_for_exec), 1334 LSM_HOOK_INIT(bprm_creds_from_file, ima_creds_check), 1335 LSM_HOOK_INIT(file_post_open, ima_file_check), 1336 LSM_HOOK_INIT(inode_post_create_tmpfile, ima_post_create_tmpfile), 1337 LSM_HOOK_INIT(file_release, ima_file_free), 1338 LSM_HOOK_INIT(mmap_file, ima_file_mmap), 1339 LSM_HOOK_INIT(file_mprotect, ima_file_mprotect), 1340 LSM_HOOK_INIT(file_truncate, ima_file_truncate), 1341 LSM_HOOK_INIT(kernel_load_data, ima_load_data), 1342 LSM_HOOK_INIT(kernel_post_load_data, ima_post_load_data), 1343 LSM_HOOK_INIT(kernel_read_file, ima_read_file), 1344 LSM_HOOK_INIT(kernel_post_read_file, ima_post_read_file), 1345 LSM_HOOK_INIT(path_post_mknod, ima_post_path_mknod), 1346 LSM_HOOK_INIT(path_truncate, ima_path_truncate), 1347 #ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS 1348 LSM_HOOK_INIT(key_post_create_or_update, ima_post_key_create_or_update), 1349 #endif 1350 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS 1351 LSM_HOOK_INIT(kernel_module_request, ima_kernel_module_request), 1352 #endif 1353 LSM_HOOK_INIT(inode_free_security_rcu, ima_inode_free_rcu), 1354 }; 1355 1356 static const struct lsm_id ima_lsmid = { 1357 .name = "ima", 1358 .id = LSM_ID_IMA, 1359 }; 1360 1361 static int __init init_ima_lsm(void) 1362 { 1363 ima_iintcache_init(); 1364 security_add_hooks(ima_hooks, ARRAY_SIZE(ima_hooks), &ima_lsmid); 1365 init_ima_appraise_lsm(&ima_lsmid); 1366 return 0; 1367 } 1368 1369 struct lsm_blob_sizes ima_blob_sizes __ro_after_init = { 1370 .lbs_inode = sizeof(struct ima_iint_cache *), 1371 }; 1372 1373 DEFINE_LSM(ima) = { 1374 .id = &ima_lsmid, 1375 .init = init_ima_lsm, 1376 .order = LSM_ORDER_LAST, 1377 .blobs = &ima_blob_sizes, 1378 /* Start IMA after the TPM is available */ 1379 .initcall_late = init_ima, 1380 }; 1381