1b886d83cSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 22fe5d6deSMimi Zohar /* 32fe5d6deSMimi Zohar * Copyright (C) 2011 IBM Corporation 42fe5d6deSMimi Zohar * 52fe5d6deSMimi Zohar * Author: 62fe5d6deSMimi Zohar * Mimi Zohar <zohar@us.ibm.com> 72fe5d6deSMimi Zohar */ 8b000d5cbSArd Biesheuvel #include <linux/module.h> 9876979c9SPaul Gortmaker #include <linux/init.h> 102fe5d6deSMimi Zohar #include <linux/file.h> 112fe5d6deSMimi Zohar #include <linux/fs.h> 122fe5d6deSMimi Zohar #include <linux/xattr.h> 132fe5d6deSMimi Zohar #include <linux/magic.h> 142fe5d6deSMimi Zohar #include <linux/ima.h> 152fe5d6deSMimi Zohar #include <linux/evm.h> 16398c42e2SMimi Zohar #include <linux/fsverity.h> 17273df864SNayna Jain #include <keys/system_keyring.h> 18398c42e2SMimi Zohar #include <uapi/linux/fsverity.h> 192fe5d6deSMimi Zohar 202fe5d6deSMimi Zohar #include "ima.h" 212fe5d6deSMimi Zohar 22e1f5e01fSMimi Zohar #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM 23b000d5cbSArd Biesheuvel static char *ima_appraise_cmdline_default __initdata; 24b000d5cbSArd Biesheuvel core_param(ima_appraise, ima_appraise_cmdline_default, charp, 0); 25b000d5cbSArd Biesheuvel 26b000d5cbSArd Biesheuvel void __init ima_appraise_parse_cmdline(void) 27b000d5cbSArd Biesheuvel { 28b000d5cbSArd Biesheuvel const char *str = ima_appraise_cmdline_default; 29e4d7e2dfSBruno Meneguele bool sb_state = arch_ima_get_secureboot(); 30e4d7e2dfSBruno Meneguele int appraisal_state = ima_appraise; 31311aa6aaSBruno Meneguele 32b000d5cbSArd Biesheuvel if (!str) 33b000d5cbSArd Biesheuvel return; 34b000d5cbSArd Biesheuvel 352fe5d6deSMimi Zohar if (strncmp(str, "off", 3) == 0) 36e4d7e2dfSBruno Meneguele appraisal_state = 0; 372faa6ef3SDmitry Kasatkin else if (strncmp(str, "log", 3) == 0) 38e4d7e2dfSBruno Meneguele appraisal_state = IMA_APPRAISE_LOG; 392fe5d6deSMimi Zohar else if (strncmp(str, "fix", 3) == 0) 40e4d7e2dfSBruno Meneguele appraisal_state = IMA_APPRAISE_FIX; 414afb28abSBruno Meneguele else if (strncmp(str, "enforce", 7) == 0) 42e4d7e2dfSBruno Meneguele appraisal_state = IMA_APPRAISE_ENFORCE; 437fe2bb7eSBruno Meneguele else 447fe2bb7eSBruno Meneguele pr_err("invalid \"%s\" appraise option", str); 45e4d7e2dfSBruno Meneguele 46e4d7e2dfSBruno Meneguele /* If appraisal state was changed, but secure boot is enabled, 47e4d7e2dfSBruno Meneguele * keep its default */ 48e4d7e2dfSBruno Meneguele if (sb_state) { 49e4d7e2dfSBruno Meneguele if (!(appraisal_state & IMA_APPRAISE_ENFORCE)) 50e4d7e2dfSBruno Meneguele pr_info("Secure boot enabled: ignoring ima_appraise=%s option", 51e4d7e2dfSBruno Meneguele str); 52e4d7e2dfSBruno Meneguele } else { 53e4d7e2dfSBruno Meneguele ima_appraise = appraisal_state; 54e4d7e2dfSBruno Meneguele } 552fe5d6deSMimi Zohar } 56b000d5cbSArd Biesheuvel #endif 572fe5d6deSMimi Zohar 582fe5d6deSMimi Zohar /* 596f6723e2SMimi Zohar * is_ima_appraise_enabled - return appraise status 606f6723e2SMimi Zohar * 616f6723e2SMimi Zohar * Only return enabled, if not in ima_appraise="fix" or "log" modes. 626f6723e2SMimi Zohar */ 636f6723e2SMimi Zohar bool is_ima_appraise_enabled(void) 646f6723e2SMimi Zohar { 65e5729f86SThiago Jung Bauermann return ima_appraise & IMA_APPRAISE_ENFORCE; 666f6723e2SMimi Zohar } 676f6723e2SMimi Zohar 686f6723e2SMimi Zohar /* 692fe5d6deSMimi Zohar * ima_must_appraise - set appraise flag 702fe5d6deSMimi Zohar * 71da1b0029SMimi Zohar * Return 1 to appraise or hash 722fe5d6deSMimi Zohar */ 73a2d2329eSChristian Brauner int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode, 74a2d2329eSChristian Brauner int mask, enum ima_hooks func) 752fe5d6deSMimi Zohar { 76d906c10dSMatthew Garrett u32 secid; 77d906c10dSMatthew Garrett 7807f6a794SMimi Zohar if (!ima_appraise) 792fe5d6deSMimi Zohar return 0; 8007f6a794SMimi Zohar 816326948fSPaul Moore security_current_getsecid_subj(&secid); 821624dc00STHOBY Simon return ima_match_policy(mnt_userns, inode, current_cred(), secid, 831624dc00STHOBY Simon func, mask, IMA_APPRAISE | IMA_HASH, NULL, 841624dc00STHOBY Simon NULL, NULL, NULL); 852fe5d6deSMimi Zohar } 862fe5d6deSMimi Zohar 87def3e8b9SDmitry Kasatkin static int ima_fix_xattr(struct dentry *dentry, 882fe5d6deSMimi Zohar struct integrity_iint_cache *iint) 892fe5d6deSMimi Zohar { 903ea7a560SDmitry Kasatkin int rc, offset; 913ea7a560SDmitry Kasatkin u8 algo = iint->ima_hash->algo; 923ea7a560SDmitry Kasatkin 933ea7a560SDmitry Kasatkin if (algo <= HASH_ALGO_SHA1) { 943ea7a560SDmitry Kasatkin offset = 1; 953ea7a560SDmitry Kasatkin iint->ima_hash->xattr.sha1.type = IMA_XATTR_DIGEST; 963ea7a560SDmitry Kasatkin } else { 973ea7a560SDmitry Kasatkin offset = 0; 983ea7a560SDmitry Kasatkin iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG; 993ea7a560SDmitry Kasatkin iint->ima_hash->xattr.ng.algo = algo; 1003ea7a560SDmitry Kasatkin } 101c7c7a1a1STycho Andersen rc = __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_IMA, 1023ea7a560SDmitry Kasatkin &iint->ima_hash->xattr.data[offset], 1033ea7a560SDmitry Kasatkin (sizeof(iint->ima_hash->xattr) - offset) + 1043ea7a560SDmitry Kasatkin iint->ima_hash->length, 0); 1053ea7a560SDmitry Kasatkin return rc; 1062fe5d6deSMimi Zohar } 1072fe5d6deSMimi Zohar 108d79d72e0SMimi Zohar /* Return specific func appraised cached result */ 109d79d72e0SMimi Zohar enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, 1104ad87a3dSMimi Zohar enum ima_hooks func) 111d79d72e0SMimi Zohar { 112d79d72e0SMimi Zohar switch (func) { 113d79d72e0SMimi Zohar case MMAP_CHECK: 114*4958db32SRoberto Sassu case MMAP_CHECK_REQPROT: 115d79d72e0SMimi Zohar return iint->ima_mmap_status; 116d79d72e0SMimi Zohar case BPRM_CHECK: 117d79d72e0SMimi Zohar return iint->ima_bprm_status; 118d906c10dSMatthew Garrett case CREDS_CHECK: 119d906c10dSMatthew Garrett return iint->ima_creds_status; 120d79d72e0SMimi Zohar case FILE_CHECK: 121c6af8efeSMimi Zohar case POST_SETATTR: 122d79d72e0SMimi Zohar return iint->ima_file_status; 123c6af8efeSMimi Zohar case MODULE_CHECK ... MAX_CHECK - 1: 124c6af8efeSMimi Zohar default: 125c6af8efeSMimi Zohar return iint->ima_read_status; 126d79d72e0SMimi Zohar } 127d79d72e0SMimi Zohar } 128d79d72e0SMimi Zohar 129d79d72e0SMimi Zohar static void ima_set_cache_status(struct integrity_iint_cache *iint, 1304ad87a3dSMimi Zohar enum ima_hooks func, 1314ad87a3dSMimi Zohar enum integrity_status status) 132d79d72e0SMimi Zohar { 133d79d72e0SMimi Zohar switch (func) { 134d79d72e0SMimi Zohar case MMAP_CHECK: 135*4958db32SRoberto Sassu case MMAP_CHECK_REQPROT: 136d79d72e0SMimi Zohar iint->ima_mmap_status = status; 137d79d72e0SMimi Zohar break; 138d79d72e0SMimi Zohar case BPRM_CHECK: 139d79d72e0SMimi Zohar iint->ima_bprm_status = status; 140d79d72e0SMimi Zohar break; 141d906c10dSMatthew Garrett case CREDS_CHECK: 142d906c10dSMatthew Garrett iint->ima_creds_status = status; 14309186e50SGustavo A. R. Silva break; 144d79d72e0SMimi Zohar case FILE_CHECK: 145c6af8efeSMimi Zohar case POST_SETATTR: 146d79d72e0SMimi Zohar iint->ima_file_status = status; 147c6af8efeSMimi Zohar break; 148c6af8efeSMimi Zohar case MODULE_CHECK ... MAX_CHECK - 1: 149c6af8efeSMimi Zohar default: 150c6af8efeSMimi Zohar iint->ima_read_status = status; 151c6af8efeSMimi Zohar break; 152d79d72e0SMimi Zohar } 153d79d72e0SMimi Zohar } 154d79d72e0SMimi Zohar 1554ad87a3dSMimi Zohar static void ima_cache_flags(struct integrity_iint_cache *iint, 1564ad87a3dSMimi Zohar enum ima_hooks func) 157d79d72e0SMimi Zohar { 158d79d72e0SMimi Zohar switch (func) { 159d79d72e0SMimi Zohar case MMAP_CHECK: 160*4958db32SRoberto Sassu case MMAP_CHECK_REQPROT: 161d79d72e0SMimi Zohar iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED); 162d79d72e0SMimi Zohar break; 163d79d72e0SMimi Zohar case BPRM_CHECK: 164d79d72e0SMimi Zohar iint->flags |= (IMA_BPRM_APPRAISED | IMA_APPRAISED); 165d79d72e0SMimi Zohar break; 166d906c10dSMatthew Garrett case CREDS_CHECK: 167d906c10dSMatthew Garrett iint->flags |= (IMA_CREDS_APPRAISED | IMA_APPRAISED); 168d906c10dSMatthew Garrett break; 169d79d72e0SMimi Zohar case FILE_CHECK: 170c6af8efeSMimi Zohar case POST_SETATTR: 171d79d72e0SMimi Zohar iint->flags |= (IMA_FILE_APPRAISED | IMA_APPRAISED); 172c6af8efeSMimi Zohar break; 173c6af8efeSMimi Zohar case MODULE_CHECK ... MAX_CHECK - 1: 174c6af8efeSMimi Zohar default: 175c6af8efeSMimi Zohar iint->flags |= (IMA_READ_APPRAISED | IMA_APPRAISED); 176c6af8efeSMimi Zohar break; 177d79d72e0SMimi Zohar } 178d79d72e0SMimi Zohar } 179d79d72e0SMimi Zohar 18050f742ddSTHOBY Simon enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, 1811525b06dSDmitry Kasatkin int xattr_len) 182d3634d0fSDmitry Kasatkin { 183d3634d0fSDmitry Kasatkin struct signature_v2_hdr *sig; 184b4bfec7fSSeth Forshee enum hash_algo ret; 185d3634d0fSDmitry Kasatkin 1863ea7a560SDmitry Kasatkin if (!xattr_value || xattr_len < 2) 1871525b06dSDmitry Kasatkin /* return default hash algo */ 1881525b06dSDmitry Kasatkin return ima_hash_algo; 189d3634d0fSDmitry Kasatkin 1903ea7a560SDmitry Kasatkin switch (xattr_value->type) { 191398c42e2SMimi Zohar case IMA_VERITY_DIGSIG: 192398c42e2SMimi Zohar sig = (typeof(sig))xattr_value; 193398c42e2SMimi Zohar if (sig->version != 3 || xattr_len <= sizeof(*sig) || 194398c42e2SMimi Zohar sig->hash_algo >= HASH_ALGO__LAST) 195398c42e2SMimi Zohar return ima_hash_algo; 196398c42e2SMimi Zohar return sig->hash_algo; 1973ea7a560SDmitry Kasatkin case EVM_IMA_XATTR_DIGSIG: 1983ea7a560SDmitry Kasatkin sig = (typeof(sig))xattr_value; 199cb181da1STHOBY Simon if (sig->version != 2 || xattr_len <= sizeof(*sig) 200cb181da1STHOBY Simon || sig->hash_algo >= HASH_ALGO__LAST) 2011525b06dSDmitry Kasatkin return ima_hash_algo; 2021525b06dSDmitry Kasatkin return sig->hash_algo; 2033ea7a560SDmitry Kasatkin case IMA_XATTR_DIGEST_NG: 204650b29dbSThiago Jung Bauermann /* first byte contains algorithm id */ 205650b29dbSThiago Jung Bauermann ret = xattr_value->data[0]; 206b4bfec7fSSeth Forshee if (ret < HASH_ALGO__LAST) 207b4bfec7fSSeth Forshee return ret; 2083ea7a560SDmitry Kasatkin break; 2093ea7a560SDmitry Kasatkin case IMA_XATTR_DIGEST: 2103ea7a560SDmitry Kasatkin /* this is for backward compatibility */ 2113ea7a560SDmitry Kasatkin if (xattr_len == 21) { 2123ea7a560SDmitry Kasatkin unsigned int zero = 0; 213650b29dbSThiago Jung Bauermann if (!memcmp(&xattr_value->data[16], &zero, 4)) 2141525b06dSDmitry Kasatkin return HASH_ALGO_MD5; 2153ea7a560SDmitry Kasatkin else 2161525b06dSDmitry Kasatkin return HASH_ALGO_SHA1; 2173ea7a560SDmitry Kasatkin } else if (xattr_len == 17) 2181525b06dSDmitry Kasatkin return HASH_ALGO_MD5; 2193ea7a560SDmitry Kasatkin break; 2203ea7a560SDmitry Kasatkin } 2211525b06dSDmitry Kasatkin 2221525b06dSDmitry Kasatkin /* return default hash algo */ 2231525b06dSDmitry Kasatkin return ima_hash_algo; 224d3634d0fSDmitry Kasatkin } 225d3634d0fSDmitry Kasatkin 226d3634d0fSDmitry Kasatkin int ima_read_xattr(struct dentry *dentry, 227f6fbd8cbSPaul Moore struct evm_ima_xattr_data **xattr_value, int xattr_len) 228d3634d0fSDmitry Kasatkin { 229f6fbd8cbSPaul Moore int ret; 230d3634d0fSDmitry Kasatkin 231c7c7a1a1STycho Andersen ret = vfs_getxattr_alloc(&init_user_ns, dentry, XATTR_NAME_IMA, 232f6fbd8cbSPaul Moore (char **)xattr_value, xattr_len, GFP_NOFS); 2335d6c3191SAndreas Gruenbacher if (ret == -EOPNOTSUPP) 2345d6c3191SAndreas Gruenbacher ret = 0; 2355d6c3191SAndreas Gruenbacher return ret; 236d3634d0fSDmitry Kasatkin } 237d3634d0fSDmitry Kasatkin 2382fe5d6deSMimi Zohar /* 239398c42e2SMimi Zohar * calc_file_id_hash - calculate the hash of the ima_file_id struct data 240398c42e2SMimi Zohar * @type: xattr type [enum evm_ima_xattr_type] 241398c42e2SMimi Zohar * @algo: hash algorithm [enum hash_algo] 242398c42e2SMimi Zohar * @digest: pointer to the digest to be hashed 243398c42e2SMimi Zohar * @hash: (out) pointer to the hash 244398c42e2SMimi Zohar * 245398c42e2SMimi Zohar * IMA signature version 3 disambiguates the data that is signed by 246398c42e2SMimi Zohar * indirectly signing the hash of the ima_file_id structure data. 247398c42e2SMimi Zohar * 248398c42e2SMimi Zohar * Signing the ima_file_id struct is currently only supported for 249398c42e2SMimi Zohar * IMA_VERITY_DIGSIG type xattrs. 250398c42e2SMimi Zohar * 251398c42e2SMimi Zohar * Return 0 on success, error code otherwise. 252398c42e2SMimi Zohar */ 253398c42e2SMimi Zohar static int calc_file_id_hash(enum evm_ima_xattr_type type, 254398c42e2SMimi Zohar enum hash_algo algo, const u8 *digest, 255398c42e2SMimi Zohar struct ima_digest_data *hash) 256398c42e2SMimi Zohar { 257398c42e2SMimi Zohar struct ima_file_id file_id = { 258398c42e2SMimi Zohar .hash_type = IMA_VERITY_DIGSIG, .hash_algorithm = algo}; 259398c42e2SMimi Zohar unsigned int unused = HASH_MAX_DIGESTSIZE - hash_digest_size[algo]; 260398c42e2SMimi Zohar 261398c42e2SMimi Zohar if (type != IMA_VERITY_DIGSIG) 262398c42e2SMimi Zohar return -EINVAL; 263398c42e2SMimi Zohar 264398c42e2SMimi Zohar memcpy(file_id.hash, digest, hash_digest_size[algo]); 265398c42e2SMimi Zohar 266398c42e2SMimi Zohar hash->algo = algo; 267398c42e2SMimi Zohar hash->length = hash_digest_size[algo]; 268398c42e2SMimi Zohar 269398c42e2SMimi Zohar return ima_calc_buffer_hash(&file_id, sizeof(file_id) - unused, hash); 270398c42e2SMimi Zohar } 271398c42e2SMimi Zohar 272398c42e2SMimi Zohar /* 273a5fbeb61SThiago Jung Bauermann * xattr_verify - verify xattr digest or signature 274a5fbeb61SThiago Jung Bauermann * 275a5fbeb61SThiago Jung Bauermann * Verify whether the hash or signature matches the file contents. 276a5fbeb61SThiago Jung Bauermann * 277a5fbeb61SThiago Jung Bauermann * Return 0 on success, error code otherwise. 278a5fbeb61SThiago Jung Bauermann */ 279a5fbeb61SThiago Jung Bauermann static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint, 280a5fbeb61SThiago Jung Bauermann struct evm_ima_xattr_data *xattr_value, int xattr_len, 281a5fbeb61SThiago Jung Bauermann enum integrity_status *status, const char **cause) 282a5fbeb61SThiago Jung Bauermann { 283398c42e2SMimi Zohar struct ima_max_digest_data hash; 284398c42e2SMimi Zohar struct signature_v2_hdr *sig; 285a5fbeb61SThiago Jung Bauermann int rc = -EINVAL, hash_start = 0; 286398c42e2SMimi Zohar int mask; 287a5fbeb61SThiago Jung Bauermann 288a5fbeb61SThiago Jung Bauermann switch (xattr_value->type) { 289a5fbeb61SThiago Jung Bauermann case IMA_XATTR_DIGEST_NG: 290a5fbeb61SThiago Jung Bauermann /* first byte contains algorithm id */ 291a5fbeb61SThiago Jung Bauermann hash_start = 1; 292df561f66SGustavo A. R. Silva fallthrough; 293a5fbeb61SThiago Jung Bauermann case IMA_XATTR_DIGEST: 2947aa5783dSRoberto Sassu if (*status != INTEGRITY_PASS_IMMUTABLE) { 295a5fbeb61SThiago Jung Bauermann if (iint->flags & IMA_DIGSIG_REQUIRED) { 296398c42e2SMimi Zohar if (iint->flags & IMA_VERITY_REQUIRED) 297398c42e2SMimi Zohar *cause = "verity-signature-required"; 298398c42e2SMimi Zohar else 299a5fbeb61SThiago Jung Bauermann *cause = "IMA-signature-required"; 300a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_FAIL; 301a5fbeb61SThiago Jung Bauermann break; 302a5fbeb61SThiago Jung Bauermann } 303a5fbeb61SThiago Jung Bauermann clear_bit(IMA_DIGSIG, &iint->atomic_flags); 3047aa5783dSRoberto Sassu } else { 3057aa5783dSRoberto Sassu set_bit(IMA_DIGSIG, &iint->atomic_flags); 3067aa5783dSRoberto Sassu } 307a5fbeb61SThiago Jung Bauermann if (xattr_len - sizeof(xattr_value->type) - hash_start >= 308a5fbeb61SThiago Jung Bauermann iint->ima_hash->length) 309a5fbeb61SThiago Jung Bauermann /* 310a5fbeb61SThiago Jung Bauermann * xattr length may be longer. md5 hash in previous 311a5fbeb61SThiago Jung Bauermann * version occupied 20 bytes in xattr, instead of 16 312a5fbeb61SThiago Jung Bauermann */ 313a5fbeb61SThiago Jung Bauermann rc = memcmp(&xattr_value->data[hash_start], 314a5fbeb61SThiago Jung Bauermann iint->ima_hash->digest, 315a5fbeb61SThiago Jung Bauermann iint->ima_hash->length); 316a5fbeb61SThiago Jung Bauermann else 317a5fbeb61SThiago Jung Bauermann rc = -EINVAL; 318a5fbeb61SThiago Jung Bauermann if (rc) { 319a5fbeb61SThiago Jung Bauermann *cause = "invalid-hash"; 320a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_FAIL; 321a5fbeb61SThiago Jung Bauermann break; 322a5fbeb61SThiago Jung Bauermann } 323a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_PASS; 324a5fbeb61SThiago Jung Bauermann break; 325a5fbeb61SThiago Jung Bauermann case EVM_IMA_XATTR_DIGSIG: 326a5fbeb61SThiago Jung Bauermann set_bit(IMA_DIGSIG, &iint->atomic_flags); 327398c42e2SMimi Zohar 328398c42e2SMimi Zohar mask = IMA_DIGSIG_REQUIRED | IMA_VERITY_REQUIRED; 329398c42e2SMimi Zohar if ((iint->flags & mask) == mask) { 330398c42e2SMimi Zohar *cause = "verity-signature-required"; 331398c42e2SMimi Zohar *status = INTEGRITY_FAIL; 332398c42e2SMimi Zohar break; 333398c42e2SMimi Zohar } 334398c42e2SMimi Zohar 335398c42e2SMimi Zohar sig = (typeof(sig))xattr_value; 336398c42e2SMimi Zohar if (sig->version >= 3) { 337398c42e2SMimi Zohar *cause = "invalid-signature-version"; 338398c42e2SMimi Zohar *status = INTEGRITY_FAIL; 339398c42e2SMimi Zohar break; 340398c42e2SMimi Zohar } 341a5fbeb61SThiago Jung Bauermann rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, 342a5fbeb61SThiago Jung Bauermann (const char *)xattr_value, 343a5fbeb61SThiago Jung Bauermann xattr_len, 344a5fbeb61SThiago Jung Bauermann iint->ima_hash->digest, 345a5fbeb61SThiago Jung Bauermann iint->ima_hash->length); 346a5fbeb61SThiago Jung Bauermann if (rc == -EOPNOTSUPP) { 347a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_UNKNOWN; 348a5fbeb61SThiago Jung Bauermann break; 349a5fbeb61SThiago Jung Bauermann } 350a5fbeb61SThiago Jung Bauermann if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc && 351a5fbeb61SThiago Jung Bauermann func == KEXEC_KERNEL_CHECK) 352a5fbeb61SThiago Jung Bauermann rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM, 353a5fbeb61SThiago Jung Bauermann (const char *)xattr_value, 354a5fbeb61SThiago Jung Bauermann xattr_len, 355a5fbeb61SThiago Jung Bauermann iint->ima_hash->digest, 356a5fbeb61SThiago Jung Bauermann iint->ima_hash->length); 357a5fbeb61SThiago Jung Bauermann if (rc) { 358a5fbeb61SThiago Jung Bauermann *cause = "invalid-signature"; 359a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_FAIL; 360a5fbeb61SThiago Jung Bauermann } else { 361a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_PASS; 362a5fbeb61SThiago Jung Bauermann } 363a5fbeb61SThiago Jung Bauermann break; 364398c42e2SMimi Zohar case IMA_VERITY_DIGSIG: 365398c42e2SMimi Zohar set_bit(IMA_DIGSIG, &iint->atomic_flags); 366398c42e2SMimi Zohar 367398c42e2SMimi Zohar if (iint->flags & IMA_DIGSIG_REQUIRED) { 368398c42e2SMimi Zohar if (!(iint->flags & IMA_VERITY_REQUIRED)) { 369398c42e2SMimi Zohar *cause = "IMA-signature-required"; 370398c42e2SMimi Zohar *status = INTEGRITY_FAIL; 371398c42e2SMimi Zohar break; 372398c42e2SMimi Zohar } 373398c42e2SMimi Zohar } 374398c42e2SMimi Zohar 375398c42e2SMimi Zohar sig = (typeof(sig))xattr_value; 376398c42e2SMimi Zohar if (sig->version != 3) { 377398c42e2SMimi Zohar *cause = "invalid-signature-version"; 378398c42e2SMimi Zohar *status = INTEGRITY_FAIL; 379398c42e2SMimi Zohar break; 380398c42e2SMimi Zohar } 381398c42e2SMimi Zohar 382398c42e2SMimi Zohar rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo, 383398c42e2SMimi Zohar iint->ima_hash->digest, &hash.hdr); 384398c42e2SMimi Zohar if (rc) { 385398c42e2SMimi Zohar *cause = "sigv3-hashing-error"; 386398c42e2SMimi Zohar *status = INTEGRITY_FAIL; 387398c42e2SMimi Zohar break; 388398c42e2SMimi Zohar } 389398c42e2SMimi Zohar 390398c42e2SMimi Zohar rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, 391398c42e2SMimi Zohar (const char *)xattr_value, 392398c42e2SMimi Zohar xattr_len, hash.digest, 393398c42e2SMimi Zohar hash.hdr.length); 394398c42e2SMimi Zohar if (rc) { 395398c42e2SMimi Zohar *cause = "invalid-verity-signature"; 396398c42e2SMimi Zohar *status = INTEGRITY_FAIL; 397398c42e2SMimi Zohar } else { 398398c42e2SMimi Zohar *status = INTEGRITY_PASS; 399398c42e2SMimi Zohar } 400398c42e2SMimi Zohar 401398c42e2SMimi Zohar break; 402a5fbeb61SThiago Jung Bauermann default: 403a5fbeb61SThiago Jung Bauermann *status = INTEGRITY_UNKNOWN; 404a5fbeb61SThiago Jung Bauermann *cause = "unknown-ima-data"; 405a5fbeb61SThiago Jung Bauermann break; 406a5fbeb61SThiago Jung Bauermann } 407a5fbeb61SThiago Jung Bauermann 408a5fbeb61SThiago Jung Bauermann return rc; 409a5fbeb61SThiago Jung Bauermann } 410a5fbeb61SThiago Jung Bauermann 411a5fbeb61SThiago Jung Bauermann /* 41239b07096SThiago Jung Bauermann * modsig_verify - verify modsig signature 41339b07096SThiago Jung Bauermann * 41439b07096SThiago Jung Bauermann * Verify whether the signature matches the file contents. 41539b07096SThiago Jung Bauermann * 41639b07096SThiago Jung Bauermann * Return 0 on success, error code otherwise. 41739b07096SThiago Jung Bauermann */ 41839b07096SThiago Jung Bauermann static int modsig_verify(enum ima_hooks func, const struct modsig *modsig, 41939b07096SThiago Jung Bauermann enum integrity_status *status, const char **cause) 42039b07096SThiago Jung Bauermann { 42139b07096SThiago Jung Bauermann int rc; 42239b07096SThiago Jung Bauermann 42339b07096SThiago Jung Bauermann rc = integrity_modsig_verify(INTEGRITY_KEYRING_IMA, modsig); 42439b07096SThiago Jung Bauermann if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc && 42539b07096SThiago Jung Bauermann func == KEXEC_KERNEL_CHECK) 42639b07096SThiago Jung Bauermann rc = integrity_modsig_verify(INTEGRITY_KEYRING_PLATFORM, 42739b07096SThiago Jung Bauermann modsig); 42839b07096SThiago Jung Bauermann if (rc) { 42939b07096SThiago Jung Bauermann *cause = "invalid-signature"; 43039b07096SThiago Jung Bauermann *status = INTEGRITY_FAIL; 43139b07096SThiago Jung Bauermann } else { 43239b07096SThiago Jung Bauermann *status = INTEGRITY_PASS; 43339b07096SThiago Jung Bauermann } 43439b07096SThiago Jung Bauermann 43539b07096SThiago Jung Bauermann return rc; 43639b07096SThiago Jung Bauermann } 43739b07096SThiago Jung Bauermann 43839b07096SThiago Jung Bauermann /* 439273df864SNayna Jain * ima_check_blacklist - determine if the binary is blacklisted. 440273df864SNayna Jain * 441273df864SNayna Jain * Add the hash of the blacklisted binary to the measurement list, based 442273df864SNayna Jain * on policy. 443273df864SNayna Jain * 444273df864SNayna Jain * Returns -EPERM if the hash is blacklisted. 445273df864SNayna Jain */ 446273df864SNayna Jain int ima_check_blacklist(struct integrity_iint_cache *iint, 447273df864SNayna Jain const struct modsig *modsig, int pcr) 448273df864SNayna Jain { 449273df864SNayna Jain enum hash_algo hash_algo; 450273df864SNayna Jain const u8 *digest = NULL; 451273df864SNayna Jain u32 digestsize = 0; 452273df864SNayna Jain int rc = 0; 453273df864SNayna Jain 454273df864SNayna Jain if (!(iint->flags & IMA_CHECK_BLACKLIST)) 455273df864SNayna Jain return 0; 456273df864SNayna Jain 457273df864SNayna Jain if (iint->flags & IMA_MODSIG_ALLOWED && modsig) { 458273df864SNayna Jain ima_get_modsig_digest(modsig, &hash_algo, &digest, &digestsize); 459273df864SNayna Jain 460273df864SNayna Jain rc = is_binary_blacklisted(digest, digestsize); 461273df864SNayna Jain if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) 462a2d2329eSChristian Brauner process_buffer_measurement(&init_user_ns, NULL, digest, digestsize, 463273df864SNayna Jain "blacklisted-hash", NONE, 464ca3c9bdbSRoberto Sassu pcr, NULL, false, NULL, 0); 465273df864SNayna Jain } 466273df864SNayna Jain 467273df864SNayna Jain return rc; 468273df864SNayna Jain } 469273df864SNayna Jain 470273df864SNayna Jain /* 4712fe5d6deSMimi Zohar * ima_appraise_measurement - appraise file measurement 4722fe5d6deSMimi Zohar * 4732fe5d6deSMimi Zohar * Call evm_verifyxattr() to verify the integrity of 'security.ima'. 4742fe5d6deSMimi Zohar * Assuming success, compare the xattr hash with the collected measurement. 4752fe5d6deSMimi Zohar * 4762fe5d6deSMimi Zohar * Return 0 on success, error code otherwise 4772fe5d6deSMimi Zohar */ 4784ad87a3dSMimi Zohar int ima_appraise_measurement(enum ima_hooks func, 4794ad87a3dSMimi Zohar struct integrity_iint_cache *iint, 480d3634d0fSDmitry Kasatkin struct file *file, const unsigned char *filename, 481d3634d0fSDmitry Kasatkin struct evm_ima_xattr_data *xattr_value, 48239b07096SThiago Jung Bauermann int xattr_len, const struct modsig *modsig) 4832fe5d6deSMimi Zohar { 48452a13284SMimi Zohar static const char op[] = "appraise_data"; 485f5e51fa3SThiago Jung Bauermann const char *cause = "unknown"; 486e71b9dffSMiklos Szeredi struct dentry *dentry = file_dentry(file); 487c6f493d6SDavid Howells struct inode *inode = d_backing_inode(dentry); 4882fe5d6deSMimi Zohar enum integrity_status status = INTEGRITY_UNKNOWN; 489a5fbeb61SThiago Jung Bauermann int rc = xattr_len; 49039b07096SThiago Jung Bauermann bool try_modsig = iint->flags & IMA_MODSIG_ALLOWED && modsig; 4912fe5d6deSMimi Zohar 49239b07096SThiago Jung Bauermann /* If not appraising a modsig, we need an xattr. */ 49339b07096SThiago Jung Bauermann if (!(inode->i_opflags & IOP_XATTR) && !try_modsig) 4942fe5d6deSMimi Zohar return INTEGRITY_UNKNOWN; 4952fe5d6deSMimi Zohar 49639b07096SThiago Jung Bauermann /* If reading the xattr failed and there's no modsig, error out. */ 49739b07096SThiago Jung Bauermann if (rc <= 0 && !try_modsig) { 4982fe5d6deSMimi Zohar if (rc && rc != -ENODATA) 4992fe5d6deSMimi Zohar goto out; 5002fe5d6deSMimi Zohar 501398c42e2SMimi Zohar if (iint->flags & IMA_DIGSIG_REQUIRED) { 502398c42e2SMimi Zohar if (iint->flags & IMA_VERITY_REQUIRED) 503398c42e2SMimi Zohar cause = "verity-signature-required"; 504398c42e2SMimi Zohar else 505398c42e2SMimi Zohar cause = "IMA-signature-required"; 506398c42e2SMimi Zohar } else { 507398c42e2SMimi Zohar cause = "missing-hash"; 508398c42e2SMimi Zohar } 509398c42e2SMimi Zohar 510b151d6b0SDmitry Kasatkin status = INTEGRITY_NOLABEL; 5116035a27bSAl Viro if (file->f_mode & FMODE_CREATED) 512b151d6b0SDmitry Kasatkin iint->flags |= IMA_NEW_FILE; 5131ac202e9SDaniel Glöckner if ((iint->flags & IMA_NEW_FILE) && 514b7e27bc1SMimi Zohar (!(iint->flags & IMA_DIGSIG_REQUIRED) || 515b7e27bc1SMimi Zohar (inode->i_size == 0))) 516b151d6b0SDmitry Kasatkin status = INTEGRITY_PASS; 5172fe5d6deSMimi Zohar goto out; 5182fe5d6deSMimi Zohar } 5192fe5d6deSMimi Zohar 520d2ee2cfcSHuaxin Lu status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, 521d2ee2cfcSHuaxin Lu rc < 0 ? 0 : rc, iint); 522f5e51fa3SThiago Jung Bauermann switch (status) { 523f5e51fa3SThiago Jung Bauermann case INTEGRITY_PASS: 524f5e51fa3SThiago Jung Bauermann case INTEGRITY_PASS_IMMUTABLE: 525f5e51fa3SThiago Jung Bauermann case INTEGRITY_UNKNOWN: 526f5e51fa3SThiago Jung Bauermann break; 527f5e51fa3SThiago Jung Bauermann case INTEGRITY_NOXATTRS: /* No EVM protected xattrs. */ 52839b07096SThiago Jung Bauermann /* It's fine not to have xattrs when using a modsig. */ 52939b07096SThiago Jung Bauermann if (try_modsig) 53039b07096SThiago Jung Bauermann break; 531df561f66SGustavo A. R. Silva fallthrough; 532f5e51fa3SThiago Jung Bauermann case INTEGRITY_NOLABEL: /* No security.evm xattr. */ 5332fe5d6deSMimi Zohar cause = "missing-HMAC"; 534f5e51fa3SThiago Jung Bauermann goto out; 535cdef685bSRoberto Sassu case INTEGRITY_FAIL_IMMUTABLE: 5367aa5783dSRoberto Sassu set_bit(IMA_DIGSIG, &iint->atomic_flags); 53755748ac6SMimi Zohar cause = "invalid-fail-immutable"; 53855748ac6SMimi Zohar goto out; 539f5e51fa3SThiago Jung Bauermann case INTEGRITY_FAIL: /* Invalid HMAC/signature. */ 5402fe5d6deSMimi Zohar cause = "invalid-HMAC"; 5412fe5d6deSMimi Zohar goto out; 542f5e51fa3SThiago Jung Bauermann default: 543f5e51fa3SThiago Jung Bauermann WARN_ONCE(true, "Unexpected integrity status %d\n", status); 5442fe5d6deSMimi Zohar } 545f5e51fa3SThiago Jung Bauermann 546a5fbeb61SThiago Jung Bauermann if (xattr_value) 547a5fbeb61SThiago Jung Bauermann rc = xattr_verify(func, iint, xattr_value, xattr_len, &status, 548a5fbeb61SThiago Jung Bauermann &cause); 5498606404fSDmitry Kasatkin 55039b07096SThiago Jung Bauermann /* 55139b07096SThiago Jung Bauermann * If we have a modsig and either no imasig or the imasig's key isn't 55239b07096SThiago Jung Bauermann * known, then try verifying the modsig. 55339b07096SThiago Jung Bauermann */ 55439b07096SThiago Jung Bauermann if (try_modsig && 55539b07096SThiago Jung Bauermann (!xattr_value || xattr_value->type == IMA_XATTR_DIGEST_NG || 55639b07096SThiago Jung Bauermann rc == -ENOKEY)) 55739b07096SThiago Jung Bauermann rc = modsig_verify(func, modsig, &status, &cause); 55839b07096SThiago Jung Bauermann 5592fe5d6deSMimi Zohar out: 56057b56ac6SMimi Zohar /* 56157b56ac6SMimi Zohar * File signatures on some filesystems can not be properly verified. 5629e67028eSMimi Zohar * When such filesystems are mounted by an untrusted mounter or on a 5639e67028eSMimi Zohar * system not willing to accept such a risk, fail the file signature 5649e67028eSMimi Zohar * verification. 56557b56ac6SMimi Zohar */ 5669e67028eSMimi Zohar if ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) && 5679e67028eSMimi Zohar ((inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) || 5689e67028eSMimi Zohar (iint->flags & IMA_FAIL_UNVERIFIABLE_SIGS))) { 56957b56ac6SMimi Zohar status = INTEGRITY_FAIL; 57057b56ac6SMimi Zohar cause = "unverifiable-signature"; 57157b56ac6SMimi Zohar integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, 57257b56ac6SMimi Zohar op, cause, rc, 0); 57357b56ac6SMimi Zohar } else if (status != INTEGRITY_PASS) { 574f5e51fa3SThiago Jung Bauermann /* Fix mode, but don't replace file signatures. */ 57539b07096SThiago Jung Bauermann if ((ima_appraise & IMA_APPRAISE_FIX) && !try_modsig && 5768606404fSDmitry Kasatkin (!xattr_value || 5778606404fSDmitry Kasatkin xattr_value->type != EVM_IMA_XATTR_DIGSIG)) { 578def3e8b9SDmitry Kasatkin if (!ima_fix_xattr(dentry, iint)) 5792fe5d6deSMimi Zohar status = INTEGRITY_PASS; 580f5e51fa3SThiago Jung Bauermann } 581f5e51fa3SThiago Jung Bauermann 5827aa5783dSRoberto Sassu /* 5837aa5783dSRoberto Sassu * Permit new files with file/EVM portable signatures, but 5847aa5783dSRoberto Sassu * without data. 5857aa5783dSRoberto Sassu */ 586f5e51fa3SThiago Jung Bauermann if (inode->i_size == 0 && iint->flags & IMA_NEW_FILE && 5877aa5783dSRoberto Sassu test_bit(IMA_DIGSIG, &iint->atomic_flags)) { 58805d1a717SMimi Zohar status = INTEGRITY_PASS; 5892fe5d6deSMimi Zohar } 590f5e51fa3SThiago Jung Bauermann 5912fe5d6deSMimi Zohar integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, 5922fe5d6deSMimi Zohar op, cause, rc, 0); 5938606404fSDmitry Kasatkin } else { 594d79d72e0SMimi Zohar ima_cache_flags(iint, func); 5952fe5d6deSMimi Zohar } 59657b56ac6SMimi Zohar 597d79d72e0SMimi Zohar ima_set_cache_status(iint, func, status); 5982fe5d6deSMimi Zohar return status; 5992fe5d6deSMimi Zohar } 6002fe5d6deSMimi Zohar 6012fe5d6deSMimi Zohar /* 6022fe5d6deSMimi Zohar * ima_update_xattr - update 'security.ima' hash value 6032fe5d6deSMimi Zohar */ 6042fe5d6deSMimi Zohar void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) 6052fe5d6deSMimi Zohar { 606e71b9dffSMiklos Szeredi struct dentry *dentry = file_dentry(file); 6072fe5d6deSMimi Zohar int rc = 0; 6082fe5d6deSMimi Zohar 6098606404fSDmitry Kasatkin /* do not collect and update hash for digital signatures */ 6100d73a552SDmitry Kasatkin if (test_bit(IMA_DIGSIG, &iint->atomic_flags)) 6118606404fSDmitry Kasatkin return; 6128606404fSDmitry Kasatkin 613da1b0029SMimi Zohar if ((iint->ima_file_status != INTEGRITY_PASS) && 614da1b0029SMimi Zohar !(iint->flags & IMA_HASH)) 615020aae3eSRoberto Sassu return; 616020aae3eSRoberto Sassu 61715588227SThiago Jung Bauermann rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo, NULL); 6182fe5d6deSMimi Zohar if (rc < 0) 6192fe5d6deSMimi Zohar return; 6208606404fSDmitry Kasatkin 6210d73a552SDmitry Kasatkin inode_lock(file_inode(file)); 6222fe5d6deSMimi Zohar ima_fix_xattr(dentry, iint); 6230d73a552SDmitry Kasatkin inode_unlock(file_inode(file)); 6242fe5d6deSMimi Zohar } 6252fe5d6deSMimi Zohar 6262fe5d6deSMimi Zohar /** 6272fe5d6deSMimi Zohar * ima_inode_post_setattr - reflect file metadata changes 628a2d2329eSChristian Brauner * @mnt_userns: user namespace of the mount the inode was found from 6292fe5d6deSMimi Zohar * @dentry: pointer to the affected dentry 6302fe5d6deSMimi Zohar * 6312fe5d6deSMimi Zohar * Changes to a dentry's metadata might result in needing to appraise. 6322fe5d6deSMimi Zohar * 6332fe5d6deSMimi Zohar * This function is called from notify_change(), which expects the caller 6342fe5d6deSMimi Zohar * to lock the inode's i_mutex. 6352fe5d6deSMimi Zohar */ 636a2d2329eSChristian Brauner void ima_inode_post_setattr(struct user_namespace *mnt_userns, 637a2d2329eSChristian Brauner struct dentry *dentry) 6382fe5d6deSMimi Zohar { 639c6f493d6SDavid Howells struct inode *inode = d_backing_inode(dentry); 6402fe5d6deSMimi Zohar struct integrity_iint_cache *iint; 641da1b0029SMimi Zohar int action; 6422fe5d6deSMimi Zohar 643a756024eSRoberto Sassu if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode) 6445d6c3191SAndreas Gruenbacher || !(inode->i_opflags & IOP_XATTR)) 6452fe5d6deSMimi Zohar return; 6462fe5d6deSMimi Zohar 647a2d2329eSChristian Brauner action = ima_must_appraise(mnt_userns, inode, MAY_ACCESS, POST_SETATTR); 6480d73a552SDmitry Kasatkin iint = integrity_iint_find(inode); 6490d73a552SDmitry Kasatkin if (iint) { 6500d73a552SDmitry Kasatkin set_bit(IMA_CHANGE_ATTR, &iint->atomic_flags); 651da1b0029SMimi Zohar if (!action) 6520d73a552SDmitry Kasatkin clear_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); 6530d73a552SDmitry Kasatkin } 6542fe5d6deSMimi Zohar } 65542c63330SMimi Zohar 65642c63330SMimi Zohar /* 65742c63330SMimi Zohar * ima_protect_xattr - protect 'security.ima' 65842c63330SMimi Zohar * 65942c63330SMimi Zohar * Ensure that not just anyone can modify or remove 'security.ima'. 66042c63330SMimi Zohar */ 66142c63330SMimi Zohar static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name, 66242c63330SMimi Zohar const void *xattr_value, size_t xattr_value_len) 66342c63330SMimi Zohar { 66442c63330SMimi Zohar if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) { 66542c63330SMimi Zohar if (!capable(CAP_SYS_ADMIN)) 66642c63330SMimi Zohar return -EPERM; 66742c63330SMimi Zohar return 1; 66842c63330SMimi Zohar } 66942c63330SMimi Zohar return 0; 67042c63330SMimi Zohar } 67142c63330SMimi Zohar 672060bdebfSMimi Zohar static void ima_reset_appraise_flags(struct inode *inode, int digsig) 67342c63330SMimi Zohar { 67442c63330SMimi Zohar struct integrity_iint_cache *iint; 67542c63330SMimi Zohar 676a756024eSRoberto Sassu if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode)) 67742c63330SMimi Zohar return; 67842c63330SMimi Zohar 67942c63330SMimi Zohar iint = integrity_iint_find(inode); 68042c63330SMimi Zohar if (!iint) 68142c63330SMimi Zohar return; 682a422638dSEric Richter iint->measured_pcrs = 0; 6830d73a552SDmitry Kasatkin set_bit(IMA_CHANGE_XATTR, &iint->atomic_flags); 684060bdebfSMimi Zohar if (digsig) 6850d73a552SDmitry Kasatkin set_bit(IMA_DIGSIG, &iint->atomic_flags); 6860d73a552SDmitry Kasatkin else 6870d73a552SDmitry Kasatkin clear_bit(IMA_DIGSIG, &iint->atomic_flags); 68842c63330SMimi Zohar } 68942c63330SMimi Zohar 69050f742ddSTHOBY Simon /** 69150f742ddSTHOBY Simon * validate_hash_algo() - Block setxattr with unsupported hash algorithms 69250f742ddSTHOBY Simon * @dentry: object of the setxattr() 69350f742ddSTHOBY Simon * @xattr_value: userland supplied xattr value 69450f742ddSTHOBY Simon * @xattr_value_len: length of xattr_value 69550f742ddSTHOBY Simon * 69650f742ddSTHOBY Simon * The xattr value is mapped to its hash algorithm, and this algorithm 69750f742ddSTHOBY Simon * must be built in the kernel for the setxattr to be allowed. 69850f742ddSTHOBY Simon * 69950f742ddSTHOBY Simon * Emit an audit message when the algorithm is invalid. 70050f742ddSTHOBY Simon * 70150f742ddSTHOBY Simon * Return: 0 on success, else an error. 70250f742ddSTHOBY Simon */ 70350f742ddSTHOBY Simon static int validate_hash_algo(struct dentry *dentry, 70450f742ddSTHOBY Simon const struct evm_ima_xattr_data *xattr_value, 70550f742ddSTHOBY Simon size_t xattr_value_len) 70650f742ddSTHOBY Simon { 70750f742ddSTHOBY Simon char *path = NULL, *pathbuf = NULL; 70850f742ddSTHOBY Simon enum hash_algo xattr_hash_algo; 7094f2946aaSTHOBY Simon const char *errmsg = "unavailable-hash-algorithm"; 7104f2946aaSTHOBY Simon unsigned int allowed_hashes; 71150f742ddSTHOBY Simon 71250f742ddSTHOBY Simon xattr_hash_algo = ima_get_hash_algo(xattr_value, xattr_value_len); 71350f742ddSTHOBY Simon 7144f2946aaSTHOBY Simon allowed_hashes = atomic_read(&ima_setxattr_allowed_hash_algorithms); 7154f2946aaSTHOBY Simon 7164f2946aaSTHOBY Simon if (allowed_hashes) { 7174f2946aaSTHOBY Simon /* success if the algorithm is allowed in the ima policy */ 7184f2946aaSTHOBY Simon if (allowed_hashes & (1U << xattr_hash_algo)) 71950f742ddSTHOBY Simon return 0; 72050f742ddSTHOBY Simon 7214f2946aaSTHOBY Simon /* 7224f2946aaSTHOBY Simon * We use a different audit message when the hash algorithm 7234f2946aaSTHOBY Simon * is denied by a policy rule, instead of not being built 7244f2946aaSTHOBY Simon * in the kernel image 7254f2946aaSTHOBY Simon */ 7264f2946aaSTHOBY Simon errmsg = "denied-hash-algorithm"; 7274f2946aaSTHOBY Simon } else { 7284f2946aaSTHOBY Simon if (likely(xattr_hash_algo == ima_hash_algo)) 7294f2946aaSTHOBY Simon return 0; 7304f2946aaSTHOBY Simon 7314f2946aaSTHOBY Simon /* allow any xattr using an algorithm built in the kernel */ 7324f2946aaSTHOBY Simon if (crypto_has_alg(hash_algo_name[xattr_hash_algo], 0, 0)) 7334f2946aaSTHOBY Simon return 0; 7344f2946aaSTHOBY Simon } 7354f2946aaSTHOBY Simon 73650f742ddSTHOBY Simon pathbuf = kmalloc(PATH_MAX, GFP_KERNEL); 73750f742ddSTHOBY Simon if (!pathbuf) 73850f742ddSTHOBY Simon return -EACCES; 73950f742ddSTHOBY Simon 74050f742ddSTHOBY Simon path = dentry_path(dentry, pathbuf, PATH_MAX); 74150f742ddSTHOBY Simon 74250f742ddSTHOBY Simon integrity_audit_msg(AUDIT_INTEGRITY_DATA, d_inode(dentry), path, 7434f2946aaSTHOBY Simon "set_data", errmsg, -EACCES, 0); 74450f742ddSTHOBY Simon 74550f742ddSTHOBY Simon kfree(pathbuf); 74650f742ddSTHOBY Simon 74750f742ddSTHOBY Simon return -EACCES; 74850f742ddSTHOBY Simon } 74950f742ddSTHOBY Simon 75042c63330SMimi Zohar int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, 75142c63330SMimi Zohar const void *xattr_value, size_t xattr_value_len) 75242c63330SMimi Zohar { 753060bdebfSMimi Zohar const struct evm_ima_xattr_data *xvalue = xattr_value; 754e3ccfe1aSRoberto Sassu int digsig = 0; 75542c63330SMimi Zohar int result; 7565926586fSMimi Zohar int err; 75742c63330SMimi Zohar 75842c63330SMimi Zohar result = ima_protect_xattr(dentry, xattr_name, xattr_value, 75942c63330SMimi Zohar xattr_value_len); 76042c63330SMimi Zohar if (result == 1) { 761a48fda9dSDmitry Kasatkin if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) 762a48fda9dSDmitry Kasatkin return -EINVAL; 7635926586fSMimi Zohar 7645926586fSMimi Zohar err = validate_hash_algo(dentry, xvalue, xattr_value_len); 7655926586fSMimi Zohar if (err) 7665926586fSMimi Zohar return err; 7675926586fSMimi Zohar 768e3ccfe1aSRoberto Sassu digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG); 7697aa5783dSRoberto Sassu } else if (!strcmp(xattr_name, XATTR_NAME_EVM) && xattr_value_len > 0) { 7707aa5783dSRoberto Sassu digsig = (xvalue->type == EVM_XATTR_PORTABLE_DIGSIG); 771e3ccfe1aSRoberto Sassu } 772e3ccfe1aSRoberto Sassu if (result == 1 || evm_revalidate_status(xattr_name)) { 773e3ccfe1aSRoberto Sassu ima_reset_appraise_flags(d_backing_inode(dentry), digsig); 7745926586fSMimi Zohar if (result == 1) 7755926586fSMimi Zohar result = 0; 77642c63330SMimi Zohar } 77742c63330SMimi Zohar return result; 77842c63330SMimi Zohar } 77942c63330SMimi Zohar 780e61b135fSChristian Brauner int ima_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, 781e61b135fSChristian Brauner const char *acl_name, struct posix_acl *kacl) 782e61b135fSChristian Brauner { 783e61b135fSChristian Brauner if (evm_revalidate_status(acl_name)) 784e61b135fSChristian Brauner ima_reset_appraise_flags(d_backing_inode(dentry), 0); 785e61b135fSChristian Brauner 786e61b135fSChristian Brauner return 0; 787e61b135fSChristian Brauner } 788e61b135fSChristian Brauner 78942c63330SMimi Zohar int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) 79042c63330SMimi Zohar { 79142c63330SMimi Zohar int result; 79242c63330SMimi Zohar 79342c63330SMimi Zohar result = ima_protect_xattr(dentry, xattr_name, NULL, 0); 794e3ccfe1aSRoberto Sassu if (result == 1 || evm_revalidate_status(xattr_name)) { 795c6f493d6SDavid Howells ima_reset_appraise_flags(d_backing_inode(dentry), 0); 796e3ccfe1aSRoberto Sassu if (result == 1) 79742c63330SMimi Zohar result = 0; 79842c63330SMimi Zohar } 79942c63330SMimi Zohar return result; 80042c63330SMimi Zohar } 801