SB20260925157 - Race condition in Linux kernel nfsd

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-93211)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

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

The vulnerability exists due to a race condition in DRC hash table initialization in nfsd_reply_cache_init when the DRC shrinker scans the reply cache before bucket list heads are initialized. A local user can trigger reply-cache initialization concurrently with a shrinker scan to cause a denial of service.

The issue occurs on weakly ordered architectures such as arm64 and ppc.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/431c70ca5163c98c746f22f16cd58ca5aefec6dc
• https://git.kernel.org/stable/c/b0c58934f5cc4f05b63ef6605dd10c1d0d489e88
• https://git.kernel.org/stable/c/b57bd8cb739cb3cf88bdb1a5903a42a707a5c282
• https://git.kernel.org/stable/c/f060f43a67635dbb393bf5dcbfc3e8b9a44942cb