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. Its 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 dont 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 its not clear why nullify the pointers at all).

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/290f1c033281c1a502a3cd1c53c3a549259c491f
• https://git.kernel.org/stable/c/3cde714b0e77206ed1b5cf31f28c18ba9ae946fd