CVE-2025-37931: Linux kernel · btrfs: adjust subpage bit start based on sectorsize
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High · fixed in 6.8.0-1046.49~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1046.49~22.04.1, 6.8.0-1051.57~22.04.1, 6.8.0-1047.50~22.04.2 +29
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux@6.8.0-100.100?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@6.8.0-1046.49?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14@6.14.0-1009.9~24.04.1?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@6.8.0-1046.52?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11@6.11.0-1018.18~24.04.1?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied. The vendor advisory from Ubuntu confirms that this issue is fixed in updated Linux kernel packages (e.g., linux-image-6.14.0-24.24 and related versions). Users should update their systems and reboot to apply the fix. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be required. No additional mitigation steps are indicated beyond applying the official update.
Description
A vulnerability in the Linux kernel's Btrfs file system was fixed that caused tree log corruption on machines with 64k page size and 16k nodesize due to incorrect handling of dirty extent buffer bitmap bits. This bug led to skipping writes of dirty metadata blocks, potentially causing file system corruption. The issue arises from improper incrementing of bitmap bits when scanning for dirty ranges, resulting in missed writes. The fix involves adjusting the bit increment logic to align with the sectors per node rather than sectorsize bits. Multiple Linux kernel versions are affected, and a patch is available.
References
- ubuntu.com/security/CVE-2025-37931 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37931 (opens in a new tab)
- git.kernel.org/linus/e08e49d986f82c30f42ad0ed43ebbede1e1e3739 (opens in a new tab)
- git.kernel.org/stable/c/396f4002710030ea1cfd4c789ebaf0a6969ab34f (opens in a new tab)
- git.kernel.org/stable/c/b80db09b614cb7edec5bada1bc7c7b0eb3b453ea (opens in a new tab)
- git.kernel.org/stable/c/e08e49d986f82c30f42ad0ed43ebbede1e1e3739 (opens in a new tab)
- ubuntu.com/security/notices/USN-7649-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7650-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7649-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7665-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7665-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7721-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-6 (opens in a new tab)