CVE-2026-74614: vsock/virtio: read virtqueues under worker locks

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

vsock/virtio: read virtqueues under worker locks

Commit bd50c5dc182b ("vsock/virtio: add support for device suspend/resume") made the run flags transition from false to true when restore installs replacement virtqueues. The RX, TX and event workers read their virtqueue before locking and checking the corresponding flag, so a worker delayed across freeze and restore can observe the replacement queue's running state while retaining a pointer to the deleted queue.

Read each virtqueue under its mutex after checking the run flag, keeping the pointer and state in the same queue generation.