CVE-2025-21755

[REJECTED CVE] A vulnerability was identified in the Linux kernel’s vsock module where the socket was orphaned before releasing the transport, leading to a NULL pointer dereference if SO_LINGER was enabled. This was caused by sock_orphan() nullifying sk->sk_wq, which was later accessed in virtio_transport_wait_close(). An attacker exploiting this flaw could trigger a kernel crash by closing a vsock socket with SO_LINGER set, leading to a denial of service on the host system.

This CVE has been rejected upstream: https://lore.kernel.org/linux-cve-announce/2025032718-REJECTED-05aa@gregkh/