CVE-2026-90379 Linux CVE debrief

Who should care

Linux kernel maintainers, Linux distribution vendors, and users of affected Linux systems should assess exposure and apply patches. System administrators and security teams should monitor for AER errors and investigate occurrences.

Why it matters

The vulnerability in the Linux kernel's mt76 Wi-Fi driver can lead to system crashes and potential DoS conditions. Linux kernel maintainers, distribution vendors, and users should assess exposure and apply patches. Monitoring system logs for AER errors is crucial.

• Potential system crashes due to invalid memory accesses.
• Possible denial-of-service (DoS) conditions.
• Need for patching and updating Linux kernel versions.
• Importance of monitoring system logs for AER errors.

Technical summary

The vulnerability occurs in the mt76 Wi-Fi driver of the Linux kernel. When an AER error happens and the bus is hung, register reads return 0xFFFFFFFF, causing corrupted DMA queue state and leading to invalid memory accesses. The fix involves validating DMA indices, clamping out-of-range values, and installing no-op bus operations on unrecoverable AER errors. This prevents system crashes and potential DoS conditions by ensuring that DMA indices are within valid ranges and that the system can recover from AER errors. Linux kernel maintainers, distribution vendors, and users of affected Linux systems should assess exposure and apply patches. Monitoring system logs for AER errors is crucial to detect and mitigate

Defensive priority

Medium

Recommended defensive actions

• Review and apply patches provided by Linux kernel maintainers to address the vulnerability.
• Ensure Linux kernel is updated to a version that includes the fix.
• Monitor system logs for AER errors and investigate occurrences.
• Review compensating controls for exposed systems while remediation is scheduled.
• Check relevant monitoring, detection, and logs for exposed assets.
• Track exceptions and retest remediated assets.
• Confirm whether affected product deployments exist in managed environments.

Evidence notes

The vulnerability was resolved by validating DMA indices and handling AER errors. The fix prevents invalid memory accesses by clamping out-of-range DMA indices and installing no-op bus operations on unrecoverable AER errors.

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.