CVE-2026-53394

high

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.

References

https://git.kernel.org/stable/c/c9aefb2b5f11337c9202c5bd0c45d71198449718

https://git.kernel.org/stable/c/a10bf67fe06469a71a401f72f328237345d553c0

https://git.kernel.org/stable/c/57aee7a35bb12753057c5b65d72d1f46c0e95b07

https://git.kernel.org/stable/c/017a6150106b054cc84d1b0582d97bd3a74d4281

Details

Source: Mitre, NVD

Published: 2026-07-19

Updated: 2026-07-20

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00168