SB2026072147 - Memory leak in Linux kernel nfsd

Description

This security bulletin contains information about 1 vulnerability.

1) Memory leak (CVE-ID: CVE-2026-53394)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

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

The vulnerability exists due to a memory leak in find_or_alloc_open_stateowner() in the NFSv4 server state handling code when processing concurrent NFSv4.0 OPEN operations with the same owner string during an unconfirmed retry race. A remote attacker can trigger repeated racing OPEN requests to cause a denial of service.

The issue requires a narrow but repeatable race condition involving two NFSv4.0 OPEN threads and a concurrent insertion of a new unconfirmed owner between retry iterations.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/017a6150106b054cc84d1b0582d97bd3a74d4281
• https://git.kernel.org/stable/c/57aee7a35bb12753057c5b65d72d1f46c0e95b07
• https://git.kernel.org/stable/c/a10bf67fe06469a71a401f72f328237345d553c0
• https://git.kernel.org/stable/c/c9aefb2b5f11337c9202c5bd0c45d71198449718