CVE-2024-26685: Linux kernel · nilfs2: fix potential bug in end_buffer_async_write
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 4.4.0-1141.147 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 4.4.0-1141.147, 4.15.0-1186.201~14.04.1, 4.4.0-266.300~14.04.1 +83
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Apr 2024
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.
Patches and advisories
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6900-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-4 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer.
References
- ubuntu.com/security/CVE-2024-26685 (opens in a new tab)
- git.kernel.org/linus/5bc09b397cbf1221f8a8aacb1152650c9195b02b (opens in a new tab)
- git.kernel.org/stable/c/c4a09fdac625e64abe478dcf88bfa20406616928 (opens in a new tab)
- git.kernel.org/stable/c/d31c8721e816eff5ca6573cc487754f357c093cd (opens in a new tab)
- git.kernel.org/stable/c/f3e4963566f58726d3265a727116a42b591f6596 (opens in a new tab)
- git.kernel.org/stable/c/8fa90634ec3e9cc50f42dd605eec60f2d146ced8 (opens in a new tab)
- git.kernel.org/stable/c/6589f0f72f8edd1fa11adce4eedbd3615f2e78ab (opens in a new tab)
- git.kernel.org/stable/c/2c3bdba00283a6c7a5b19481a59a730f46063803 (opens in a new tab)
- git.kernel.org/stable/c/626daab3811b772086aef1bf8eed3ffe6f523eff (opens in a new tab)
- git.kernel.org/stable/c/5bc09b397cbf1221f8a8aacb1152650c9195b02b (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26685 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-2 (opens in a new tab)