Linux Kernel Interconnect Locking Vulnerability in Runtime Power Management

A vulnerability in the Linux kernel's interconnect management can lead to a deadlock situation during runtime power management operations. This issue arises because the function 'icc_bw_set()' can be called in contexts that interfere with memory reclamation processes, such as during the resumption of runtime power management. The problem is caused by a circular locking dependency, where one lock is waiting for another to be released, creating a deadlock scenario. The vulnerability affects Linux kernel versions through 6.2.0-rc8-debug.

Impact

Exploitation of this vulnerability can cause a deadlock, where two or more processes are unable to proceed because each is waiting for the other to release a resource, potentially leading to a system hang.

Reproduction

The vulnerability can be reproduced by invoking the 'icc_bw_set()' function during a 'runpm resume' operation, which triggers the circular locking dependency. This can be done by creating a scenario where the interconnect bandwidth settings are updated while the system is reclaiming memory, such as during the initialization of the CPU topology or when adding interconnect nodes.

Remediation

Users can upgrade to the latest stable version of the Linux kernel, where this vulnerability has been addressed, to avoid this locking issue.