CVE-2026-53394

nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race

HIGH
7.5
CVSS Score
Published: July 19, 2026 at 12:01 PM UTC
Updated: October 19, 2026 at 08:19 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race When find_or_alloc_open_stateowner() encounters an unconfirmed owner, it calls release_openowner() and sets oo = NULL. Control then falls through past the `if (oo)` guard -- which would have freed any pre-allocated `new` -- and unconditionally executes `new = alloc_stateowner(...)`. If `new` was already allocated on a prior iteration, the pointer is silently overwritten and the previous allocation (slab object + owner name buffer) is leaked. This requires a race: two NFSv4.0 OPEN threads with the same owner string, where a concurrent thread inserts a new unconfirmed owner into the hash between retry iterations. The window is narrow but repeatable under adversarial conditions. Fix by adding `goto retry` after `oo = NULL` so the already-allocated `new` is reused on the next iteration rather than overwritten.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.10 ≤ v < 6.12.956.13 ≤ v < 6.18.386.19 ≤ v < 7.1.323df17788c6212809848f836b10c4f85b16843a56.10
Vendor states this is fixed in 017a6150106b054cc84d1b0582d97bd3a74d4281 (fixed)
Vendor states this is fixed in 57aee7a35bb12753057c5b65d72d1f46c0e95b07 (fixed)
Vendor states this is fixed in a10bf67fe06469a71a401f72f328237345d553c0 (fixed)
Vendor states this is fixed in c9aefb2b5f11337c9202c5bd0c45d71198449718 (fixed)
Vendor states this is fixed in 6.10 (unaffected)
Vendor states this is fixed in 6.12.95 (unaffected)
Vendor states this is fixed in 6.18.38 (unaffected)
Vendor states this is fixed in 7.1.3 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-401

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