Use After Free in Linux

CVE-2024-44932

In the Linux kernel, the following vulnerability has been resolved: idpf: fix UAFs when destroying the queues The second tagged commit started sometimes (very rarely, but possible) throwing WARNs from net/core/page_pool.c:page_pool_disable_direct_recycling(). Turned out idpf frees interrupt vectors with embedded NAPIs *before* freeing the queues making page_pools' NAPI pointers lead to freed memory before these pools are destroyed by libeth. It's not clear whether there are other accesses to the freed vectors when destroying the queues, but anyway, we usually free queue/interrupt vectors only when the queues are destroyed and the NAPIs are guaranteed to not be referenced anywhere. Invert the allocation and freeing logic making queue/interrupt vectors be allocated first and freed last. Vectors don't require queues to be present, so this is safe. Additionally, this change allows to remove that useless queue->q_vector pointer cleanup, as vectors are still valid when freeing the queues (+ both are freed within one function, so it's not clear why nullify the pointers at all).

Vulnerability class: Use-After-Free

EPSS: 0.002 (13.9th percentile) — read the EPSS interpretation.