Description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix recvmsg() unconditional requeue If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at the front of the recvmsg queue already has its mutex locked, it requeues the call - whether or not the call is already queued. The call may be on the queue because MSG_PEEK was also passed and so the call was not dequeued or because the I/O thread requeued it. The unconditional requeue may then corrupt the recvmsg queue, leading to things like UAFs or refcount underruns. Fix this by only requeuing the call if it isn't already on the queue - and moving it to the front if it is already queued. If we don't queue it, we have to put the ref we obtained by dequeuing it. Also, MSG_PEEK doesn't dequeue the call so shouldn't call rxrpc_notify_socket() for the call if we didn't use up all the data on the queue, so fix that also.
Product status
540b1c48c37ac0ad66212004db21e1ff7e2d78be (git) before 930114425065f7ace6e0c0630fab4af75e059ea8
540b1c48c37ac0ad66212004db21e1ff7e2d78be (git) before 2c28769a51deb6022d7fbd499987e237a01dd63a
4.11
Any version before 4.11
6.18.8 (semver)
6.19 (original_commit_for_fix)
References
git.kernel.org/...c/930114425065f7ace6e0c0630fab4af75e059ea8
git.kernel.org/...c/2c28769a51deb6022d7fbd499987e237a01dd63a