Commit 2cb7c756 authored by Stefano Garzarella's avatar Stefano Garzarella Committed by Paolo Abeni
Browse files

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.

Fixes: c0cfa2d8 ("vsock: add multi-transports support")
Cc: stable@vger.kernel.org
Reported-by: default avatarHyunwoo Kim <v4bel@theori.io>
Reported-by: default avatarWongi Lee <qwerty@theori.io>
Closes: https://lore.kernel.org/netdev/Z2LvdTTQR7dBmPb5@v4bel-B760M-AORUS-ELITE-AX/


Signed-off-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Reviewed-by: default avatarHyunwoo Kim <v4bel@theori.io>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 0865b9fd

net/vmw_vsock/virtio_transport_common.c

+5 −2
Original line number Diff line number Diff line
@@ -1628,8 +1628,11 @@ void virtio_transport_recv_pkt(struct virtio_transport *t, 


	lock_sock(sk);



	/* Check if sk has been closed before lock_sock */

	if (sock_flag(sk, SOCK_DONE)) {

	/* Check if sk has been closed or assigned to another transport before

	 * lock_sock (note: listener sockets are not assigned to any transport)

	 */

	if (sock_flag(sk, SOCK_DONE) ||

	    (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) {

		(void)virtio_transport_reset_no_sock(t, skb);

		release_sock(sk);

		sock_put(sk);