CVE-2026-89644btrfs: fix extent map leak in NOCOW direct I/O write
- —Not scoredno CVSS score yet
- 0.17%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map leak in NOCOW direct I/O write btrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an extent map reference that must be dropped on all exit paths. For direct writes into a NOCOW range, btrfs_get_blocks_direct_write() keeps using that extent map and asks btrfs_create_dio_extent() to allocate the ordered extent. If that fails, for example because btrfs_alloc_ordered_extent() fails, the function returns the error without dropping the input extent map. The PREALLOC path avoided this by dropping the input extent map before replacing it with the newly created one. Check the error from btrfs_create_dio_extent() before replacing the map and drop the input extent map on failure.
Timeline
ID reserved
By Linux
Published
- 49 days later
· 49 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.17% · top 93% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af – < 8d264d35df981e943171ddc09cd6cc1d38c65e17
- affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af – < cb732d302245b14943a5017015fffa8e6db7a6c0
- affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af – < b7c873765875645b11503f94c9bae2ca80127375
- affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af – < f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2
- affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af – < 05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d
- affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af – < 3f950867c307c5413d628a153ac44915bd117ffd
- affected 4.7
- unaffected < 4.7
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.111 – ≤ 6.12.*
- unaffected 6.18.50 – ≤ 6.18.*
- unaffected 7.2.4 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References6
- https://git.kernel.org/stable/c/8d264d35df981e943171ddc09cd6cc1d38c65e17 (opens in a new tab)
- https://git.kernel.org/stable/c/cb732d302245b14943a5017015fffa8e6db7a6c0 (opens in a new tab)
- https://git.kernel.org/stable/c/b7c873765875645b11503f94c9bae2ca80127375 (opens in a new tab)
- https://git.kernel.org/stable/c/f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2 (opens in a new tab)
- https://git.kernel.org/stable/c/05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d (opens in a new tab)
- https://git.kernel.org/stable/c/3f950867c307c5413d628a153ac44915bd117ffd (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-76556 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-89644)Record last updated .