Linux Kernel Radix Tree Deadlock Vulnerability in DMA Debug API

A potential deadlock vulnerability has been identified in the Linux kernel's DMA debug API, specifically within the handling of the radix tree. The issue arises when the radix lock is held while also managing DMA hash entries, creating a scenario where two CPUs can block each other. This deadlock can occur during certain synchronization operations or while interacting with performance events on ARM Cortex hardware tracing drivers.

Impact

Exploitation of this vulnerability can lead to a deadlock situation, causing the system to hang or become unresponsive.

Remediation

The vulnerability has been addressed by modifying the order of operations in the DMA debug API. Users should ensure they are running a version of the Linux kernel that includes this fix.