Linux Kernel Netpoll Memory Allocation Deadlock Vulnerability

A deadlock vulnerability has been identified in the Linux kernel's netpoll feature, specifically within the memory allocation process under spinlock. This issue arises in the refill_skbs() function, where holding the skb_pool->lock while allocating memory can lead to a recursive lock acquisition attempt, causing a deadlock. The problem is exacerbated during periods of high memory pressure, when the memory allocation fails and triggers an out-of-memory warning. This warning is processed in a way that attempts to reacquire the same lock, which is already held, leading to a deadlock situation.

Impact

Exploitation of this vulnerability causes a deadlock, where the system becomes unresponsive due to a circular locking situation.

Remediation

The vulnerability has been addressed in the Linux kernel. Users should upgrade to the latest version where this issue has been fixed.