rxrpc: Fix missing locking causing hanging calls

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix missing locking causing hanging calls If a call gets aborted (e.g. because kafs saw a signal) between it being queued for connection and the I/O thread picking up the call, the abort will be prioritised over the connection and it will be removed from local->new_client_calls by rxrpc_disconnect_client_call() without a lock being held. This may cause other calls on the list to disappear if a race occurs. Fix this by taking the client_call_lock when removing a call from whatever list its ->wait_link happens to be on.

References

• https://git.kernel.org/stable/c/996a7208dadbf2cdda8d51444d5ee1fdd1ccbc92
• https://git.kernel.org/stable/c/b1fdb0bb3b6513f5bd26f92369fd6ac1a2422d8b
• https://git.kernel.org/stable/c/fc9de52de38f656399d2ce40f7349a6b5f86e787