In the Linux kernel, the following vulnerability has been resolved: RDMA/cma: Fix hang when cma_netevent_callback fails to queue_work The cited commit fixed a crash when cma_netevent_callback was called for a cma_id while work on that id from a previous call had not yet started. The work item was re-initialized in the second call, which corrupted the work item currently in the work queue. However, it left a problem when queue_work fails (because the item is still pending in the work queue from a previous call). In this case, cma_id_put (which is called in the work handler) is therefore not called. This results in a userspace process hang (zombie process). Fix this by calling cma_id_put() if queue_work fails.
https://git.kernel.org/stable/c/ac7897c0124066b9705ffca252a3662d54fc0c9b
https://git.kernel.org/stable/c/92a251c3df8ea1991cd9fe00f1ab0cfce18d7711
https://git.kernel.org/stable/c/8b05aa3692e45b8249379dc52b14acc6a104d2e5
https://git.kernel.org/stable/c/1ac40736c8c4255d8417b937c9715b193f4a87b3
https://git.kernel.org/stable/c/02e45168e0fd6fdc6f8f7c42c4b500857aa5efb0