CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's NAT keepalive functionality, which can lead to a deadlock condition due to improper lock management during state table traversal. This issue arises when the nat_keepalive_work function conflicts with the state deletion process, potentially causing system hangs. Organizations using affected Linux kernel versions, particularly those relying on NAT features, should prioritize applying the patch to mitigate this deadlock risk.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: avoid lock inversion in nat keepalive work nat_keepalive_work() walks the state table while xfrm_state_walk() holds net->xfrm.xfrm_state_lock. Its callback then acquires x->lock, which conflicts with the delete path taking the same locks in reverse order via xfrm_state_delete() and __xfrm_state_delete(). This creates an AB-BA deadlock that is reported by lockdep when a NAT keepalive worker races with SA deletion. Fix this by splitting the keepalive walk into two phases. First, collect the candidate states while the walk holds xfrm_state_lock and take a reference on each state. Then, after the walk completes, process each collected state and acquire x->lock without nesting it under xfrm_state_lock.