CVE-2025-21669

In the Linux kernel, the following vulnerability has been resolved:

vsock/virtio: discard packets if the transport changes

If the socket has been de-assigned or assigned to another transport, we must discard any packets received because they are not expected and would cause issues when we access vsk->transport.

A possible scenario is described by Hyunwoo Kim in the attached link, where after a first connect() interrupted by a signal, and a second connect() failed, we can find vsk->transport at NULL, leading to a NULL pointer dereference.