Commit aaa3149b authored by Jason Wang's avatar Jason Wang Committed by David S. Miller

vhost_net: add missing lock nesting notation

We try to hold TX virtqueue mutex in vhost_net_rx_peek_head_len()
after RX virtqueue mutex is held in handle_rx(). This requires an
appropriate lock nesting notation to calm down deadlock detector.

Fixes: 03088137 ("vhost_net: basic polling support")
Reported-by: syzbot+7f073540b1384a614e09@syzkaller.appspotmail.com
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f3d801ba
...@@ -630,7 +630,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) ...@@ -630,7 +630,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk)
if (!len && vq->busyloop_timeout) { if (!len && vq->busyloop_timeout) {
/* Both tx vq and rx socket were polled here */ /* Both tx vq and rx socket were polled here */
mutex_lock(&vq->mutex); mutex_lock_nested(&vq->mutex, 1);
vhost_disable_notify(&net->dev, vq); vhost_disable_notify(&net->dev, vq);
preempt_disable(); preempt_disable();
...@@ -763,7 +763,7 @@ static void handle_rx(struct vhost_net *net) ...@@ -763,7 +763,7 @@ static void handle_rx(struct vhost_net *net)
struct iov_iter fixup; struct iov_iter fixup;
__virtio16 num_buffers; __virtio16 num_buffers;
mutex_lock(&vq->mutex); mutex_lock_nested(&vq->mutex, 0);
sock = vq->private_data; sock = vq->private_data;
if (!sock) if (!sock)
goto out; goto out;
......
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