- 5.5MediumCVSS base score
- 0.12%Exploitation in 30 daysEPSS · top 98% 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: ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O When allocating blocks during within-EOF DIO and writeback with dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was set when calling ext4_split_convert_extents(), which may potentially result in stale data issues. Assume we have an unwritten extent, and then DIO writes the second half. [UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUUUUUU] extent status tree |<- ->| ----> dio write this range First, ext4_iomap_alloc() call ext4_map_blocks() with EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the above flags set. Then, ext4_split_convert_extents() calls ext4_split_extent() with EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2 flags set, and it calls ext4_split_extent_at() to split the second half with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at() failed to insert extent since a temporary lack -ENOSPC. It zeroes out the first half but convert the entire on-disk extent to written since the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten in the extent status tree. [0000000000SSSSSS] data S: stale data, 0: zeroed [WWWWWWWWWWWWWWWW] on-disk extent W: written extent [WWWWWWWWWWUUUUUU] extent status tree Finally, if the DIO failed to write data to the disk, the stale data in the second half will be exposed once the cached extent entry is gone. Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting an unwritten extent before submitting I/O, and make ext4_split_convert_extents() to zero out the entire extent range to zero for this case, and also mark the extent in the extent status tree for consistency.
Timeline
ID reserved
By Linux
- 14 days later
· 14 days later
Published
- 5 months later
· 5 months 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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.12% · top 98% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 77e407967cd872cd75d7e4a691908e49c8e6b4d4
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 37555690f39f78ef69af347d9aff897e07445949
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 6d8fa684b42724d74a77f980f5ee47cfd1ec7e74
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 67cdb7bd7442bd3cdc6d6088bbb2df9be2fe936c
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 2920ec61c98b9476781359f05b94da84e80f54d4
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 2698731d25823267c29190cb578da9296a0c0d7b
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < 716e7439a5a9b18c3ff882c2f8c834b9ced1aaec
- affected b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 – < feaf2a80e78f89ee8a3464126077ba8683b62791
- affected 3.15
- unaffected < 3.15
- unaffected 5.10.253 – ≤ 5.10.*
- unaffected 5.15.203 – ≤ 5.15.*
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.130 – ≤ 6.6.*
- unaffected 6.12.77 – ≤ 6.12.*
- unaffected 6.18.17 – ≤ 6.18.*
- unaffected 6.19.4 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References8
- https://git.kernel.org/stable/c/77e407967cd872cd75d7e4a691908e49c8e6b4d4 (opens in a new tab)
- https://git.kernel.org/stable/c/37555690f39f78ef69af347d9aff897e07445949 (opens in a new tab)
- https://git.kernel.org/stable/c/6d8fa684b42724d74a77f980f5ee47cfd1ec7e74 (opens in a new tab)
- https://git.kernel.org/stable/c/67cdb7bd7442bd3cdc6d6088bbb2df9be2fe936c (opens in a new tab)
- https://git.kernel.org/stable/c/2920ec61c98b9476781359f05b94da84e80f54d4 (opens in a new tab)
- https://git.kernel.org/stable/c/2698731d25823267c29190cb578da9296a0c0d7b (opens in a new tab)
- https://git.kernel.org/stable/c/716e7439a5a9b18c3ff882c2f8c834b9ced1aaec (opens in a new tab)
- https://git.kernel.org/stable/c/feaf2a80e78f89ee8a3464126077ba8683b62791 (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-2026-32270 (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-2026-45985)Record last updated .