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VulnerabilityPublished Updated

CVE-2026-72472: Linux kernel · nfs: use nfsi->rwsem to protect traversal of the file lock list

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-1013.13~24.04.1 : patch Linux kernel as a priority.

Data as of 28 Oct 2026, 00:59 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 7.0.0-1013.13~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +13
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-34.34
Fixed in
  • 7.0.0-34.34
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1013.13
Fixed in
  • 7.0.0-1013.13
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1017.17
Fixed in
  • 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1016.16
Fixed in
  • 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1013.13
Fixed in
  • 7.0.0-1013.13
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1007.8
Fixed in
  • 7.0.0-1007.8

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: nfs: use nfsi->rwsem to protect traversal of the file lock list Lingfeng identified a bug and suggested two solutions, but both appear to have issues. Generally, we cannot release flc_lock while iterating over the file lock list to avoid use-after-free (UAF) problems with file locks. However, functions like nfs_delegation_claim_locks and nfs4_reclaim_locks cannot adhere to this rule because recover_lock or nfs4_lock_delegation_recall may take a long time. To resolve this, NFS switches to using nfsi->rwsem for the same protection, and nfs_reclaim_locks follows this approach. Although nfs_delegation_claim_locks uses so_delegreturn_mutex instead, this is inadequate since a single inode can have multiple nfs4_state instances. Therefore, the fix is to also use nfsi->rwsem in this case. Furthermore, after commit c69899a17ca4 ("NFSv4: Update of VFS byte range lock must be atomic with the stateid update"), the functions nfs4_locku_done and nfs4_lock_done also break this rule because they call locks_lock_inode_wait without holding nfsi->rwsem. Simply adding this protection could cause many deadlocks, so instead, the call to locks_lock_inode_wait is moved into _nfs4_proc_setlk. Regarding the bug fixed by commit c69899a17ca4 ("NFSv4: Update of VFS byte range lock must be atomic with the stateid update"), it has been resolved after commit 0460253913e5 ("NFSv4: nfs4_do_open() is incorrectly triggering state recovery") because all slots are drained before calling nfs4_do_reclaim, which prevents concurrent stateid changes along this path. Also, nfs_delegation_claim_locks does not cause this concurrency either since when _nfs4_proc_setlk is called with NFS_DELEGATED_STATE, no RPC is sent, so nfs4_lock_done is not called. Therefore, nfs4_lock_delegation_recall from nfs_delegation_claim_locks is the first time the stateid is set.

References

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