vhost_net: zerocopy: fix possible NULL pointer dereference of vq->bufs
When we want to disable vhost_net backend while there's a tx work, a possible
NULL pointer defernece may happen we we try to deference the vq->bufs after
vhost_net_set_backend() assign a NULL to it.
As suggested by Michael, fix this by checking the vq->bufs instead of
vhost_sock_zcopy().
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 1f21d2a..35abe90 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -166,7 +166,7 @@
if (wmem < sock->sk->sk_sndbuf / 2)
tx_poll_stop(net);
hdr_size = vq->vhost_hlen;
- zcopy = vhost_sock_zcopy(sock);
+ zcopy = vq->ubufs;
for (;;) {
/* Release DMAs done buffers first */