Linux hwe edge: In the Linux kernel, the following vulnerability has been resolved: xfrm: avoid lock inversion in nat keepalive work nat_keepalive_work() walks the… (CVE-2026-80845)

The vulnerability in the Linux kernel involves the xfrm NAT keepalive worker function nat_keepalive_work() walking the state table while holding the xfrm_state_lock. During this process, a callback acquires another lock (x->lock), which conflicts with the reverse lock acquisition order in the delete path (xfrm_state_delete and __xfrm_state_delete). This lock inversion can cause an AB-BA deadlock when the NAT keepalive worker races with SA deletion. The issue was fixed by restructuring the keepalive walk into two phases: first collecting candidate states while holding the xfrm_state_lock and taking references, then processing each state and acquiring x->lock outside the nested lock context.

This deadlock vulnerability can cause kernel hangs or stalls when the NAT keepalive worker and SA deletion operations occur concurrently, potentially impacting system stability and availability. There is no indication of code execution or privilege escalation from this issue.

A fix has been implemented that restructures the locking mechanism to avoid deadlocks. Users should apply the official Linux kernel updates that include this fix. Since no patch links or vendor advisories are provided in the data, check the official Linux kernel repositories or vendor advisories for the specific patch and update instructions.