CVE-2026-93231 Linux CVE debrief

Who should care

Linux kernel maintainers, administrators of systems using NFS, and security teams responsible for patching and vulnerability management should be aware of this vulnerability and take necessary actions to prevent lockd issues. System administrators should review and apply kernel updates to ensure the fix is deployed. Security teams should monitor system logs for potential lockd-related errors and implement compensating controls for exposed systems.

Why it matters

A fix was applied to the Linux kernel to address a vulnerability in the lockd subsystem. The vulnerability could prevent locks from being released when requested by IP address.

• Verify and apply kernel updates to prevent lockd issues
• Review system logs for potential lockd problems
• Ensure proper validation of /proc/fs/nfsd/unlock_ip usage

Technical summary

The nlmsvc_match_ip() function in the Linux kernel's lockd subsystem had its arguments reversed, preventing locks from being released when requested by IP address. This has been fixed in the kernel. The fix addresses the issue by swapping the arguments to ensure proper lock release. The vulnerability could be exploited to cause denial-of-service attacks. Technical teams should review and apply kernel updates to ensure the fix is deployed. The fix is specific to the Linux kernel's lockd subsystem and does not affect other kernel components.

Defensive priority

Verify and apply kernel updates to ensure the fix is deployed.

Recommended defensive actions

• Verify kernel version and apply updates if necessary
• Review system logs for potential lockd issues
• Ensure /proc/fs/nfsd/unlock_ip usage is properly validated
• Monitor system logs for lockd-related errors
• Perform regular vulnerability scans to detect potential issues
• Implement compensating controls for exposed systems
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and source references indicate a fix was applied to the Linux kernel to address the argument reversal in nlmsvc_match_ip(). The fix was introduced to prevent locks from not being released when requested by IP address. The source references provide additional information on the Linux kernel fix. Evidence is limited to public CVE and NVD records.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.