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authorJason Wang <jasowang@redhat.com>2018-03-26 16:10:23 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-12 12:31:21 +0200
commit94f1b8485ce3e6fd0b736ae7c671838eaee2c21c (patch)
parenta17ab0a5c81cd646d7cc14e54dd97aa1205e3ab4 (diff)
vhost_net: add missing lock nesting notation
[ Upstream commit aaa3149bbee9ba9b4e6f0bd6e3e7d191edeae942 ] 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> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 5636c7ca8eba..0020ae906bf9 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -618,7 +618,7 @@ 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);
@@ -751,7 +751,7 @@ 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;