CVE-2026-80790 Linux CVE debrief

Who should care

System administrators and security teams responsible for Linux kernel-based systems, especially those using NVMeoF, should assess their exposure and apply the provided patches to mitigate the vulnerability.

Why it matters

CVE-2026-80790 is a Linux kernel vulnerability in the nvmet-fc component that can cause an invalid free in the LS IOD error path. This vulnerability can be triggered with specific configurations and tools. The fix involves correctly freeing the original allocation base. System administrators and security teams should review and apply patches, verify fixes, and monitor for potential exploitation attempts.

• Verify patch application to prevent potential DoS
• Assess exposure of NVMeoF configurations
• Monitor for exploitation attempts in Linux kernel environments
• Review system configurations for potential workarounds

Technical summary

The Linux kernel vulnerability CVE-2026-80790 is related to the nvmet-fc component, which is part of the NVMe over Fabrics (NVMeoF) implementation. The vulnerability occurs in the LS IOD (I/O Descriptor) error path, where an invalid free operation can happen. This can lead to memory corruption and potentially cause a denial-of-service (DoS) or other unspecified impacts. The fix involves correctly freeing the original allocation base stored in tgtport->iod instead of the advanced iod. The vulnerability can be triggered with specific configurations and tools like nvme-fcloop and failslab.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the provided patches to ensure the vulnerability is fixed.
• Verify the fix with testing and validation.
• Monitor for any potential exploitation attempts.
• Assess exposure of NVMeoF configurations.
• Verify patch application to prevent potential DoS.
• Review system configurations for potential workarounds.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and affected systems. Additional information is available from source references. The vulnerability can be reproduced with nvme-fcloop and failslab by setting fail-nth to 6 before creating a target port. KASAN reports a BUG: KASAN: invalid-free in nvmet_fc_register_targetport. Free of addr ffff88816cf8ff48 by task nvmet_fail_nth/9552.

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.