{"id":"CVE-2026-74671","summary":"ima: fix out-of-bounds read in xattr_verify()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nima: fix out-of-bounds read in xattr_verify()\n\nThe digest-length check in xattr_verify() mixes int and size_t:\n\n\tif (xattr_len - sizeof(xattr_value-\u003etype) - hash_start \u003e=\n\t\t\tiint-\u003eima_hash-\u003elength)\n\nsizeof() yields size_t, so the usual arithmetic conversions promote\nthe whole left-hand side to unsigned 64-bit before the subtraction\nruns. For a truncated xattr this underflows instead of going negative:\na 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)\nturns \"1 - 1 - 1\" into SIZE_MAX, which is trivially \u003e= ima_hash-\u003elength.\nThe check then passes and the following memcmp() reads\niint-\u003eima_hash-\u003elength bytes starting past the end of the buffer\nvfs_getxattr_alloc() allocated for it.\n\nNothing upstream clamps xattr_len back into a safe range first:\nima_get_hash_algo() only special-cases xattr_len \u003c 2 to pick a default\nalgorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than\nfailing when no HMAC key is loaded, so a truncated security.ima value\nreaches the length check as-is.\n\nRewrite the comparison so every operand stays a signed int and no\nimplicit conversion to size_t can occur.","modified":"2026-08-24T11:47:21.314544586Z","published":"2026-08-22T15:32:41.480Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74671.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/27f3924061592d0ef6b04e16f48754b6cb6adf27"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5ff232d31106f45ac87c3b64e1d35a0667777797"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7e515b6c9aab452a4f0734bd7208e4e780e164ca"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a784b4732ac7e51862b9b210c2d8b2ab9e83568c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b6cb134707a2127d90a58d69dd818679cae8033c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/caeb105c15ea2431fa8da7ecfa242d0c68272426"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d823b5f4557083d1dd92096f796a78a2b1b06d10"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dd04114af0d451091f7b8cbd26d9e37d011e9131"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74671.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74671"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3ea7a56067e663278470c04fd655adf809e72d4d"},{"fixed":"d823b5f4557083d1dd92096f796a78a2b1b06d10"},{"fixed":"caeb105c15ea2431fa8da7ecfa242d0c68272426"},{"fixed":"a784b4732ac7e51862b9b210c2d8b2ab9e83568c"},{"fixed":"b6cb134707a2127d90a58d69dd818679cae8033c"},{"fixed":"7e515b6c9aab452a4f0734bd7208e4e780e164ca"},{"fixed":"27f3924061592d0ef6b04e16f48754b6cb6adf27"},{"fixed":"dd04114af0d451091f7b8cbd26d9e37d011e9131"},{"fixed":"5ff232d31106f45ac87c3b64e1d35a0667777797"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74671.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.13.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.152"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.104"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.45"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74671.json"}}],"schema_version":"1.9.0"}