CVE-2025-38724: nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-04 · updated 2026-10-19
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm() Lei Lu recently reported that nfsd4_setclientid_confirm() did not check the return value from get_client_locked(). a SETCLIENTID_CONFIRM could race with a confirmed client expiring and fail to get a reference. That could later lead to a UAF. Fix this by getting a reference early in the case where there is an extant confirmed client. If that fails then treat it as if there were no confirmed client found at all. In the case where the unconfirmed client is expiring, just fail and return the result from get_client_locked().

Affected products

Debian Linux: 11.0
Linux kernel: from 3.17 before 5.4.297; from 5.5 before 5.10.241; from 5.11 before 5.15.190; from 5.16 before 6.1.149; from 6.2 before 6.6.103; from 6.7 before 6.12.43 — fixed in 5.10.241, 5.15.190, 5.4.297, 6.1.149, 6.12.43, 6.15.11

How to fix

Upgrade to a fixed version: Linux kernel 5.10.241, 5.15.190, 5.4.297, 6.1.149. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-38724 or the next vulnerability affects your stack