CVE-2026-93042 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel systems, particularly those using the affected versions, should assess exposure and prioritize patching. This includes operators managing Linux kernel deployments, vulnerability management teams, and security teams responsible for ensuring the security and integrity of Linux-based systems.

Why it matters

Defenders should prioritize patching and verifying system configurations for this Linux kernel vulnerability to prevent potential data breaches, system crashes, and exploitation.

• Potential for data breaches due to use-after-free errors
• Possible system crashes or instability due to descriptor leaks
• Required verification of patch application and system configuration
• Potential for attackers to exploit this vulnerability to gain elevated privileges

Technical summary

The Linux kernel's dmaengine dw-edma has a vulnerability that can cause a late callback after dmaengine_terminate_sync() to dereference client state that has already been freed, while leftover descriptors may later restart into reused buffers or leak. The vulnerability is resolved by moving all issued and submitted descriptors to the terminated list whenever termination completes. This change ensures that no callback functions will be called for any incomplete transfers, preventing potential data breaches and system crashes.

Defensive priority

Defenders should prioritize verifying and applying patches for this vulnerability, particularly for systems using the affected Linux kernel versions.

Recommended defensive actions

• Verify and apply patches for this vulnerability
• Review system configurations and ensure that dmaengine dw-edma is properly configured
• Monitor system logs for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and NVD vulnerability detail provide information on the vulnerability, including its description, CVSS score, and references to source code changes. The vulnerability occurs because the dw-edma calls vchan_cookie_complete() when a deferred STOP reaches the interrupt handler, which schedules a callback for the active descriptor and leaves other issued or submitted descriptors queued. This can cause a late callback after dmaengine_terminate_sync() to dereference client state that has already been freed, while leftover

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.