CVE-2026-98515 Linux CVE debrief

Who should care

Linux kernel developers and administrators who use the nouveau driver should assess their exposure and apply the provided patches to fix the vulnerability. The vulnerability can cause denial of service, elevation of privileges, and memory corruption. Review and apply the provided kernel patches to fix the double-free vulnerability. Update Linux kernel to the latest version. Monitor system logs for potential exploitation attempts.

Why it matters

The CVE-2026-98515 double-free vulnerability in the Linux kernel's nouveau driver requires immediate attention from Linux kernel developers and administrators. The vulnerability can lead to potential denial of service (DoS), elevation of privileges, and memory corruption. To mitigate the vulnerability, review and apply the provided kernel patches, update Linux kernel to the latest version, and monitor system logs for potential exploitation attempts.

• Potential denial of service (DoS) due to double-free
• Possible elevation of privileges
• Memory corruption and potential code execution

Technical summary

The vulnerability occurs in the `nvif_vmm_dtor` function, where the `vmm->page` is freed unconditionally. However, the `vmm->page` is not cleared after being freed, leading to a double-free when the function is called again. The vulnerability can cause denial of service, elevation of privileges, and memory corruption. The provided stack trace shows the call sequence leading to the double-free. Linux kernel developers and administrators should assess their exposure and apply the provided patches to fix the vulnerability.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the provided kernel patches to fix the double-free vulnerability
• Update Linux kernel to the latest version
• Monitor system logs 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 vulnerability was found by fuzzing the nouveau driver with a modified Syzkaller. The stack trace and memory allocation information were provided. The vulnerability occurs in the `nvif_vmm_dtor` function, where the `vmm->page` is freed unconditionally. However, the `vmm->page` is not cleared after being freed, leading to a double-free when the function is called again. The provided stack trace shows the call sequence leading to the double-free.

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.