In the Linux kernel, the following vulnerability has been resolved: RDMA/cm: Fix leaking the multicast GID table reference If the CM ID is destroyed while the CM event for multicast creating is still queued the cancel_work_sync() will prevent the work from running which also prevents destroying the ah_attr. This leaks a refcount and triggers a WARN: GID entry ref leak for dev syz1 index 2 ref=573 WARNING: CPU: 1 PID: 655 at drivers/infiniband/core/cache.c:809 release_gid_table drivers/infiniband/core/cache.c:806 [inline] WARNING: CPU: 1 PID: 655 at drivers/infiniband/core/cache.c:809 gid_table_release_one+0x284/0x3cc drivers/infiniband/core/cache.c:886 Destroy the ah_attr after canceling the work, it is safe to call this twice.
https://git.kernel.org/stable/c/c0acdee513239e1d6e1b490f56be0e6837dfd162
https://git.kernel.org/stable/c/ab668a58c4a2ccb6d54add7a76f2f955d15d0196
https://git.kernel.org/stable/c/5cb34bb5fd726491b809efbeb5cfd63ae5bf9cf3
https://git.kernel.org/stable/c/57f3cb6c84159d12ba343574df2115fb18dd83ca
https://git.kernel.org/stable/c/3ba6d01c4b3c584264dc733c6a2ecc5bbc8e0bb5