CVE-2026-23465: Linux kernel · btrfs: log new dentries when logging parent dir of a conflicting inode
Source GCVE Database
Not known to be exploited · CVSS 5.5 High · fixed in f556b1e09d054e31f464c0fd37280c2b5a393fee : patch Linux kernel soon.
Data as of 30 Oct 2026, 16:33 UTC
Thin evidence
One scorer or none- Patch
- Available – fixed in f556b1e09d054e31f464c0fd37280c2b5a393fee, 9573a365ff9ff45da9222d3fe63695ce562beb24, 56e72c8b02d982be775d9df025357c152383ee84 +3
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 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: log new dentries when logging parent dir of a conflicting inode If we log the parent directory of a conflicting inode, we are not logging the new dentries of the directory, so when we finish we have the parent directory's inode marked as logged but we did not log its new dentries. As a consequence if the parent directory is explicitly fsynced later and it does not have any new changes since we logged it, the fsync is a no-op and after a power failure the new dentries are missing. Example scenario: $ mkdir foo $ sync $rmdir foo $ mkdir dir1 $ mkdir dir2 # A file with the same name and parent as the directory we just deleted # and was persisted in a past transaction. So the deleted directory's # inode is a conflicting inode of this new file's inode. $ touch foo $ ln foo dir2/link # The fsync on dir2 will log the parent directory (".") because the # conflicting inode (deleted directory) does not exists anymore, but it # it does not log its new dentries (dir1). $ xfs_io -c "fsync" dir2 # This fsync on the parent directory is no-op, since the previous fsync # logged it (but without logging its new dentries). $ xfs_io -c "fsync" . <power failure> # After log replay dir1 is missing. Fix this by ensuring we log new dir dentries whenever we log the parent directory of a no longer existing conflicting inode. A test case for fstests will follow soon.
References
- nvd.nist.gov/vuln/detail/CVE-2026-23465 (opens in a new tab)
- git.kernel.org/stable/c/1cf30c73602c69d750c9345c47f2c0e9d0cfb578 (opens in a new tab)
- git.kernel.org/stable/c/56e72c8b02d982be775d9df025357c152383ee84 (opens in a new tab)
- git.kernel.org/stable/c/6c23595c54cfeb878e3fbbb8eb08bc5061d0c2d4 (opens in a new tab)
- git.kernel.org/stable/c/6f5a51969b1deb79aefd2194b48fe7e78e72ff7e (opens in a new tab)
- git.kernel.org/stable/c/9573a365ff9ff45da9222d3fe63695ce562beb24 (opens in a new tab)
- git.kernel.org/stable/c/f556b1e09d054e31f464c0fd37280c2b5a393fee (opens in a new tab)