{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89787", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.766Z", "datePublished": "2026-09-16T08:48:24.403Z", "dateUpdated": "2026-10-19T08:52:40.961Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:52:40.961Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: check dir entry fits before reading the hash trailer in ext4_search_dir()\n\nFor casefolded encrypted directories ext4 stores an 8-byte hash trailer\nafter the name (EXT4_DIRENT_HASHES()), at an offset derived from\nde->name_len. On the sb_no_casefold_compat_fallback() path ext4_match()\nreads that trailer, but ext4_search_dir()'s by-hand pre-check only tests\nde->name + de->name_len <= dlimit, which proves the name fits, not the\nrounded trailer. A crafted entry whose name ends at the block boundary\npasses the check while EXT4_DIRENT_HASHES(de) lands past the block end,\nso ext4_match() reads out of bounds on an ordinary lookup. KASAN reports\nit as a use-after-free when the page after the directory block holds a\nfreed object:\n\n BUG: KASAN: use-after-free in ext4_match (fs/ext4/namei.c:1435)\n Read of size 4 at addr ffff888010458000 by task exploit\n Call Trace:\n ext4_match (fs/ext4/namei.c:1435)\n ext4_search_dir (fs/ext4/namei.c:1470)\n __ext4_find_entry (fs/ext4/namei.c:1268 fs/ext4/namei.c:1632)\n ext4_lookup (fs/ext4/namei.c:1703 fs/ext4/namei.c:1769)\n ...\n filename_lookup (fs/namei.c:2842)\n vfs_statx (fs/stat.c:353)\n __do_sys_newfstatat (fs/stat.c:538)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nRequire, for hash-in-dirent directories, that the whole entry including\nthe rounded trailer fits before calling ext4_match(). This is the same\nbound ext4_check_dir_entry() already enforces via ext4_dir_rec_len(), so\nno well-formed entry is rejected. The other caller, ext4_find_dest_de(),\nruns ext4_check_dir_entry() first and is unaffected." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/namei.c" ], "versions": [ { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "4d20106c536b73c4a8a02652dc85e35898baebf7", "status": "affected", "versionType": "git" }, { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "61a395967de06edba58760e81907a272db749faa", "status": "affected", "versionType": "git" }, { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "e94676a08af6312aa72d8a981232b281f9bcfcf5", "status": "affected", "versionType": "git" }, { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "d8c184bec24b5a00ae96d704856d935eaded1685", "status": "affected", "versionType": "git" }, { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "3933884bc3102898b458c53fbd1ac52eb9cdb8a4", "status": "affected", "versionType": "git" }, { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "83663c0b739480c00cfe785675db87520ec484ed", "status": "affected", "versionType": "git" }, { "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "lessThan": "c7e6b863d298f56522d0d08554bbea7f142e6588", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/namei.c" ], "versions": [ { "version": "5.13", "status": "affected" }, { "version": "0", "lessThan": "5.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4d20106c536b73c4a8a02652dc85e35898baebf7" }, { "url": "https://git.kernel.org/stable/c/61a395967de06edba58760e81907a272db749faa" }, { "url": "https://git.kernel.org/stable/c/e94676a08af6312aa72d8a981232b281f9bcfcf5" }, { "url": "https://git.kernel.org/stable/c/d8c184bec24b5a00ae96d704856d935eaded1685" }, { "url": "https://git.kernel.org/stable/c/3933884bc3102898b458c53fbd1ac52eb9cdb8a4" }, { "url": "https://git.kernel.org/stable/c/83663c0b739480c00cfe785675db87520ec484ed" }, { "url": "https://git.kernel.org/stable/c/c7e6b863d298f56522d0d08554bbea7f142e6588" } ], "title": "ext4: check dir entry fits before reading the hash trailer in ext4_search_dir()", "x_generator": { "engine": "bippy-1.2.0" } } } }