| Message ID | 1522051823-5166-1-git-send-email-jasowang@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Mar 26, 2018 at 04:10:23PM +0800, Jason Wang wrote: > 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: 0308813724606 ("vhost_net: basic polling support") > Reported-by: syzbot+7f073540b1384a614e09@syzkaller.appspotmail.com > Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/vhost/net.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 8139bc7..12bcfba 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -630,7 +630,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) > > if (!len && vq->busyloop_timeout) { > /* 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); > > preempt_disable(); > @@ -763,7 +763,7 @@ static void handle_rx(struct vhost_net *net) > struct iov_iter fixup; > __virtio16 num_buffers; > > - mutex_lock(&vq->mutex); > + mutex_lock_nested(&vq->mutex, 0); > sock = vq->private_data; > if (!sock) > goto out; > -- > 2.7.4
From: Jason Wang <jasowang@redhat.com> Date: Mon, 26 Mar 2018 16:10:23 +0800 > 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: 0308813724606 ("vhost_net: basic polling support") > Reported-by: syzbot+7f073540b1384a614e09@syzkaller.appspotmail.com > Signed-off-by: Jason Wang <jasowang@redhat.com> Applied and queued up for -stable, thanks Jason.
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 8139bc7..12bcfba 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -630,7 +630,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) if (!len && vq->busyloop_timeout) { /* 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); preempt_disable(); @@ -763,7 +763,7 @@ static void handle_rx(struct vhost_net *net) struct iov_iter fixup; __virtio16 num_buffers; - mutex_lock(&vq->mutex); + mutex_lock_nested(&vq->mutex, 0); sock = vq->private_data; if (!sock) goto out;
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: 0308813724606 ("vhost_net: basic polling support") Reported-by: syzbot+7f073540b1384a614e09@syzkaller.appspotmail.com Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/vhost/net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)