From: Stefano Garzarella sgarzare@redhat.com
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: 06a8fc78367d ("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 --- net/vmw_vsock/virtio_transport_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1029,10 +1029,10 @@ void virtio_transport_recv_pkt(struct vi
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;