| From foo@baz Wed Apr 11 10:26:56 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 |
| @@ -211,8 +211,7 @@ 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; |
| } |
| |
