SB2026072135 - Use-after-free in Linux kernel nfsd

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-53399)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to a use-after-free in the nfsd layout stateid handling in fs/nfsd/nfs4layouts.c when processing layout stateid allocation failures after a setlease error. A remote user can trigger a setlease failure and subsequent IDR walker access to dereference a dangling pointer to cause a denial of service.

The issue occurs because a published stateid remains referenced in the IDR after the associated memory is freed, and a related destructor path may access uninitialized delayed work on the same failure path.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/30d55c8aabb261bc3f427d6b9aae7ef6206063f9
• https://git.kernel.org/stable/c/83c2b7797742339bb768f83935f7ca33950db138
• https://git.kernel.org/stable/c/8dee7c278f1c2b5bb80e17a6281c3812fc8b0cdd
• https://git.kernel.org/stable/c/d369e5edfaaf83a448016e2f1da392b2174be801