rxrpc: Fix oops due to non-existence of prealloc backlog struct

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CVE-2025-38514

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix oops due to non-existence of prealloc backlog struct If an AFRXRPC service socket is opened and bound, but calls are preallocated, then rxrpcallocincomingcall will oops because the rxrpcbacklog struct doesn't get...

CVE-2025-38514

The CVE-2025-38514 issue affects the Linux kernel RxRPC: when an AF_RXRPC service socket is opened/bound and calls are preallocated, rxrpc_alloc_incoming_call() can oops because rxrpc_backlog may not be allocated until the first preallocation. The fix is to return NULL from rxrpc_alloc_incoming_c...