This is a note to let you know that I've just added the patch titled
vhost_net: add missing lock nesting notation
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vhost_net-add-missing-lock-nesting-notation.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Apr 11 10:26:56 CEST 2018
From: Jason Wang <jasowang@xxxxxxxxxx>
Date: Mon, 26 Mar 2018 16:10:23 +0800
Subject: vhost_net: add missing lock nesting notation
From: Jason Wang <jasowang@xxxxxxxxxx>
[ 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@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vhost/net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -524,7 +524,7 @@ static int vhost_net_rx_peek_head_len(st
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();
@@ -657,7 +657,7 @@ static void handle_rx(struct vhost_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;
Patches currently in stable-queue which might be from jasowang@xxxxxxxxxx are
queue-4.9/skbuff-return-emsgsize-in-skb_to_sgvec-to-prevent-overflow.patch
queue-4.9/virtio_net-check-return-value-of-skb_to_sgvec-always.patch
queue-4.9/vhost-validate-log-when-iotlb-is-enabled.patch
queue-4.9/vhost_net-add-missing-lock-nesting-notation.patch
queue-4.9/vhost-correctly-remove-wait-queue-during-poll-failure.patch
queue-4.9/virtio_net-check-return-value-of-skb_to_sgvec-in-one-more-location.patch