vsock/virtio: update credit only if socket is not closed

commit ce7536bc7398e2ae552d2fabb7e0e371a9f1fe46 upstream.

If the socket is closed or is being released, some resources used by
virtio_transport_space_update() such as 'vsk->trans' may be released.

To avoid a use after free bug we should only update the available credit
when we are sure the socket is still open and we have the lock held.

Fixes: 06a8fc7836 ("VSOCK: Introduce virtio_vsock_common.ko")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20210208144454.84438-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stefano Garzarella 2021-02-08 15:44:54 +01:00 committed by Greg Kroah-Hartman
parent 2545c5bd83
commit c025081b57

View File

@ -1100,10 +1100,10 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
vsk = vsock_sk(sk);
space_available = virtio_transport_space_update(sk, pkt);
lock_sock(sk);
space_available = virtio_transport_space_update(sk, pkt);
/* Update CID in case it has changed after a transport reset event */
vsk->local_addr.svm_cid = dst.svm_cid;