CVE-2026-97931 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux-based systems should be aware of this vulnerability and take necessary actions to ensure their systems are secure. This includes verifying Linux kernel versions and configurations, restricting access to hwdep nodes, and monitoring for potential exploitation attempts. Additionally, users with O_RDWR access to hwdep nodes should be cautious of the potential risks and take

Why it matters

A vulnerability in the Linux kernel's ALSA us122l component has been addressed, allowing a process with O_RDWR access to make the mapping writable using mprotect().

• Verify Linux kernel versions and configurations to ensure the fix is applied
• Restrict access to hwdep nodes to prevent unauthorized modifications
• Monitor for potential exploitation attempts

Technical summary

The Linux kernel's ALSA us122l component had a vulnerability where the hwdep mmap callback did not properly reject read-buffer mappings that were initially writable. A process with O_RDWR access could use mprotect() to make the mapping writable, potentially accessing pages beyond the allocation or releasing pages outside the allocation. The fix clears VM_MAYWRITE for read-buffer mappings, preventing later permission upgrades and ensuring the security of the system. This change does not affect the output-buffer mapping, which remains writable.

Defensive priority

Verify Linux kernel versions and configurations; restrict access to hwdep nodes

Recommended defensive actions

• Verify Linux kernel versions and configurations to ensure the fix is applied
• Restrict access to hwdep nodes to prevent unauthorized modifications
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Kernel references are available but limited. A detailed analysis of the Linux kernel's ALSA us122l component reveals that the hwdep mmap callback did not properly reject read-buffer mappings that were initially writable. This oversight allowed a process with O_RDWR access to make the mapping writable using mprotect(), potentially leading to accessing pages beyond the allocation or releasing pages outside the allocation. The fix, which clears VM_MAYWRITE for read-buffer

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.