Linux Kernel IRQ Affinity Hint Vulnerability in STMMAC Network Driver

A vulnerability in the Linux kernel's STMMAC network driver was addressed, concerning improper management of the IRQ affinity hint. The issue arose because the cpumask was defined as a local variable, while its pointer could be accessed from procfs after being saved to irq_desc, potentially leading to the use of freed memory. The vulnerability has been resolved by ensuring the cpumask is persistent, using cpumask_of(cpu#) to maintain its validity.

Impact

Exploitation of this vulnerability could lead to use-after-free conditions, where freed memory is accessed, potentially causing memory corruption or allowing for arbitrary code execution.