Answer in brief
CVE-2026-89787 records a Unknown severity vulnerability in ext4: check dir entry fits before reading the hash trailer in ext4_search_dir(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <4d20106c536b73c4a8a02652dc85e35898baebf7 || >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <61a395967de06edba58760e81907a272db749faa || >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <e94676a08af6312aa72d8a981232b281f9bcfcf5 || >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <d8c184bec24b5a00ae96d704856d935eaded1685 || >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <3933884bc3102898b458c53fbd1ac52eb9cdb8a4 || >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <83663c0b739480c00cfe785675db87520ec484ed || >=471fbbea7ff7061b2d6474665cb5a2ceb4fd6500 <c7e6b863d298f56522d0d08554bbea7f142e6588 | 4d20106c536b73c4a8a02652dc85e35898baebf7, 61a395967de06edba58760e81907a272db749faa, e94676a08af6312aa72d8a981232b281f9bcfcf5, d8c184bec24b5a00ae96d704856d935eaded1685, 3933884bc3102898b458c53fbd1ac52eb9cdb8a4, 83663c0b739480c00cfe785675db87520ec484ed, c7e6b863d298f56522d0d08554bbea7f142e6588 |
| Linux/Linuxgeneric | 5.13 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
In the Linux kernel, the following vulnerability has been resolved: ext4: check dir entry fits before reading the hash trailer in ext4_search_dir() For casefolded encrypted directories ext4 stores an 8-byte hash trailer after the name (EXT4_DIRENT_HASHES()), at an offset derived from de->name_len. On the sb_no_casefold_compat_fallback() path ext4_match() reads that trailer, but ext4_search_dir()'s by-hand pre-check only tests de->name + de->name_len <= dlimit, which proves the name fits, not the rounded trailer. A crafted entry whose name ends at the block boundary passes the check while EXT4_DIRENT_HASHES(de) lands past the block end, so ext4_match() reads out of bounds on an ordinary lookup. KASAN reports it as a use-after-free when the page after the directory block holds a freed object: BUG: KASAN: use-after-free in ext4_match (fs/ext4/namei.c:1435) Read of size 4 at addr ffff888010458000 by task exploit Call Trace: ext4_match (fs/ext4/namei.c:1435) ext4_search_dir (fs/ext4/namei.c:1470) __ext4_find_entry (fs/ext4/namei.c:1268 fs/ext4/namei.c:1632) ext4_lookup (fs/ext4/namei.c:1703 fs/ext4/namei.c:1769) ... filename_lookup (fs/namei.c:2842) vfs_statx (fs/stat.c:353) __do_sys_newfstatat (fs/stat.c:538) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Require, for hash-in-dirent directories, that the whole entry including the rounded trailer fits before calling ext4_match(). This is the same bound ext4_check_dir_entry() already enforces via ext4_dir_rec_len(), so no well-formed entry is rejected. The other caller, ext4_find_dest_de(), runs ext4_check_dir_entry() first and is unaffected.
Quoted source text, attributed separately from HOL analysis.