Question: What is CVE-2025-21669?
Answer: CVE-2025-21669 is a vulnerability classified as medium with a CVSS score of 5.5. It falls under CWE-476 and affects the system as follows: 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.