CVE-2026-46256
Received Received - Intake
Direct reclaim deadlock in Linux kernel NFS LOCALIO

Publication date: 2026-06-03

Last updated on: 2026-06-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages LOCALIO is an NFS loopback mount optimization that avoids using the network for READ, WRITE and COMMIT if the NFS client and server are determined to be on the same system. But because LOCALIO is still fundamentally "just NFS loopback mount" it is susceptible to recursion deadlock via direct reclaim, e.g.: NFS LOCALIO down to XFS and then back into NFS via nfs_writepages. Fix LOCALIO's potential for direct reclaim deadlock by ensuring that all its page cache allocations are done from GFP_NOFS context. Thanks to Ben Coddington for pointing out commit ad22c7a043c2 ("xfs: prevent stack overflows from page cache allocation").
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Meta Information
Published
2026-06-03
Last Modified
2026-06-03
Generated
2026-06-04
AI Q&A
2026-06-03
EPSS Evaluated
N/A
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's NFS LOCALIO feature, which is an optimization that allows NFS clients and servers on the same system to avoid using the network for certain operations like READ, WRITE, and COMMIT.

Because LOCALIO is essentially an NFS loopback mount, it is vulnerable to a recursion deadlock caused by direct reclaim. Specifically, this can happen when NFS LOCALIO operations go down to the XFS filesystem and then back into NFS through the nfs_writepages function.

The issue is fixed by ensuring that all page cache allocations in LOCALIO are done from the GFP_NOFS context, which prevents the direct reclaim recursion deadlock.


How can this vulnerability impact me? :

This vulnerability can cause a recursion deadlock in the Linux kernel when using NFS LOCALIO, potentially leading to system hangs or degraded performance during file operations involving NFS and XFS.

Such deadlocks can affect system stability and availability, especially on systems relying on NFS LOCALIO for optimized local file access.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability in the Linux kernel related to NFS LOCALIO causing potential direct reclaim recursion deadlock has been fixed by ensuring all page cache allocations are done from GFP_NOFS context.

To mitigate this vulnerability immediately, you should update your Linux kernel to a version that includes this fix.


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