CVE-2021-47024

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

vsock/virtio: free queued packets when closing socket

As reported by syzbot [1], there is a memory leak while closing the socket. We partially solved this issue with commit ac03046ece2b ("vsock/virtio: free packets during the socket release"), but we forgot to drain the RX queue when the socket is definitely closed by the scheduled work.

To avoid future issues, let's use the new virtio_transport_remove_sock() to drain the RX queue before removing the socket from the af_vsock lists calling vsock_remove_sock().

[1] https://syzkaller.appspot.com/bug?extid=24452624fc4c571eedd9

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.