CVE-2026-89787

{"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"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/ext4/namei.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "4d20106c536b73c4a8a02652dc85e35898baebf7", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}, {"lessThan": "61a395967de06edba58760e81907a272db749faa", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}, {"lessThan": "e94676a08af6312aa72d8a981232b281f9bcfcf5", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}, {"lessThan": "d8c184bec24b5a00ae96d704856d935eaded1685", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}, {"lessThan": "3933884bc3102898b458c53fbd1ac52eb9cdb8a4", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}, {"lessThan": "83663c0b739480c00cfe785675db87520ec484ed", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}, {"lessThan": "c7e6b863d298f56522d0d08554bbea7f142e6588", "status": "affected", "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/ext4/namei.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.13"}, {"lessThan": "5.13", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.221", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.188", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.110", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.52", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}], "id": "CVE-2026-89787", "lastModified": "2026-10-19T09:18:22.340", "metrics": {}, "published": "2026-09-16T09:17:09.460", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3933884bc3102898b458c53fbd1ac52eb9cdb8a4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4d20106c536b73c4a8a02652dc85e35898baebf7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/61a395967de06edba58760e81907a272db749faa"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/83663c0b739480c00cfe785675db87520ec484ed"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c7e6b863d298f56522d0d08554bbea7f142e6588"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d8c184bec24b5a00ae96d704856d935eaded1685"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e94676a08af6312aa72d8a981232b281f9bcfcf5"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,4d20106c536b73c4a8a02652dc85e35898baebf7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,61a395967de06edba58760e81907a272db749faa)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,e94676a08af6312aa72d8a981232b281f9bcfcf5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,d8c184bec24b5a00ae96d704856d935eaded1685)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,3933884bc3102898b458c53fbd1ac52eb9cdb8a4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,83663c0b739480c00cfe785675db87520ec484ed)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[471fbbea7ff7061b2d6474665cb5a2ceb4fd6500,c7e6b863d298f56522d0d08554bbea7f142e6588)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "5.13"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.13)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.15.221,5.16.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.188,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.157,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.110,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.52,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.6,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-16T14:15:09.531306+00:00", "updated": "2026-09-20T04:45:16.997965+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-119"]}