From c460f0573941cb28dc7f35595679c3508f0ce41f Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Wed, 2 May 2012 11:42:23 +0800
Subject: [PATCH] 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>
---
drivers/vhost/net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 1f21d2a1e528..35abe9019ba7 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -166,7 +166,7 @@ static void handle_tx(struct vhost_net *net)
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 */
--
2.20.1