This is a note to let you know that I've just added the patch titled

vhost: correctly remove wait queue during poll failure

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: vhost-correctly-remove-wait-queue-during-poll-failure.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Tue Apr 10 23:20:08 CEST 2018

From: Jason Wang jasowang@redhat.com Date: Tue, 27 Mar 2018 20:50:52 +0800 Subject: vhost: correctly remove wait queue during poll failure

From: Jason Wang jasowang@redhat.com

[ Upstream commit dc6455a71c7fc5117977e197f67f71b49f27baba ]

We tried to remove vq poll from wait queue, but do not check whether or not it was in a list before. This will lead double free. Fixing this by switching to use vhost_poll_stop() which zeros poll->wqh after removing poll from waitqueue to make sure it won't be freed twice.

Cc: Darren Kenny darren.kenny@oracle.com Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") Signed-off-by: Jason Wang jasowang@redhat.com Reviewed-by: Darren Kenny darren.kenny@oracle.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 --- drivers/vhost/vhost.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -213,8 +213,7 @@ int vhost_poll_start(struct vhost_poll * if (mask) vhost_poll_wakeup(&poll->wait, 0, 0, (void *)mask); if (mask & POLLERR) { - if (poll->wqh) - remove_wait_queue(poll->wqh, &poll->wait); + vhost_poll_stop(poll); ret = -EINVAL; }

Patches currently in stable-queue which might be from jasowang@redhat.com are

queue-4.14/vhost-validate-log-when-iotlb-is-enabled.patch queue-4.14/vhost_net-add-missing-lock-nesting-notation.patch queue-4.14/vhost-correctly-remove-wait-queue-during-poll-failure.patch