CVE-2021-47616

In the Linux kernel, the following vulnerability has been resolved:

RDMA: Fix use-after-free in rxe_queue_cleanup

On error handling path in rxe_qp_from_init() qp->sq.queue is freed and then rxe_create_qp() will drop last reference to this object. qp clean up function will try to free this queue one time and it causes UAF bug.

Fix it by zeroing queue pointer after freeing queue in rxe_qp_from_init().

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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/84b01721e8042cdd1e8ffeb648844a09cd4213e0
• https://git.kernel.org/stable/c/acb53e47db1fbc7cd37ab10b46388f045a76e383
• https://git.kernel.org/stable/c/84b01721e8042cdd1e8ffeb648844a09cd4213e0
• https://git.kernel.org/stable/c/acb53e47db1fbc7cd37ab10b46388f045a76e383