Bug 2436778 (CVE-2026-23053)

Summary: CVE-2026-23053 kernel: Linux kernel: Denial of Service in NFSv4.1 client due to deadlock during memory reclaim
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel. An NFSv4.1 client can experience a deadlock during memory reclaim. This occurs when state recovery waits on kthreadd while kthreadd attempts to reclaim memory by calling nfs_release_folio(), leading to a circular dependency. A local user can trigger this condition by initiating page cache activity on an NFS mount, resulting in hung tasks, system-wide stalls, and a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-02-04 17:02:56 UTC 
In the Linux kernel, the following vulnerability has been resolved:

NFS: Fix a deadlock involving nfs_release_folio()

Wang Zhaolong reports a deadlock involving NFSv4.1 state recovery
waiting on kthreadd, which is attempting to reclaim memory by calling
nfs_release_folio(). The latter cannot make progress due to state
recovery being needed.

It seems that the only safe thing to do here is to kick off a writeback
of the folio, without waiting for completion, or else kicking off an
asynchronous commit.
Comment 1 Jon Moroney 2026-02-05 00:05:14 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026020451-CVE-2026-23053-f630@gregkh/T