In the Linux kernel, the following vulnerability has been resolved:
rxrpc: serialize kernel accept preallocation with socket teardown
rxrpc_kernel_charge_accept() reads rx->backlog without any socket/backlog synchronization and passes that raw pointer into rxrpc_service_prealloc_one(). A concurrent rxrpc_discard_prealloc() sets rx->backlog = NULL and frees the backlog rings, so a kernel preallocation worker can keep using a freed struct rxrpc_backlog while updating *_backlog_head/tail and array slots.
Serialize the state check and backlog lookup with the socket lock, and reject kernel preallocation once teardown has disabled listening or discarded the service backlog.
References
- https://git.kernel.org/stable/c/0337cdba0c477f176c0459bed012109453184573
- https://git.kernel.org/stable/c/1741378a7a83dfd8e53a9196730df709b903cd33
- https://git.kernel.org/stable/c/35a967ff8b24db09ee429c39c5b5e6571639997d
- https://git.kernel.org/stable/c/dc175389b18c29a5303ee83169ec653adfae3e17
- https://git.kernel.org/stable/c/dfa0b2bbc5e50119f89c6b5407faa5ed86dfa7c5