In the Linux kernel, the following vulnerability has been resolved:
net/iucv: fix use-after-free of a severed iucv_path
af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connections iucv_path. When the peer severs the connection, iucv_sever_path() frees that path with iucv_path_free() but leaves the notifications queued. A later recvmsg() drains message_q via iucv_process_message_q() and hands the stale path to message_receive() – a use-after-free of the freed iucv_path.
Drop the queued notifications when the path is severed; once the path is gone they can no longer be received. This also frees the notifications leaked when a socket is closed with messages still queued.
References
- https://git.kernel.org/stable/c/23658b350b4107e8292045c2044983fd426fa15d
- https://git.kernel.org/stable/c/900cd6d8119b7f3ae5c4bf82f922ff5957df43db
- https://git.kernel.org/stable/c/a5bbaddf69853117f28173c3f5c8fc14c6b2ec82
- https://git.kernel.org/stable/c/be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a
- https://git.kernel.org/stable/c/f579582c03ed526281a8450159baf1d35099a85f