Jason Wang
2018-Mar-27 03:47 UTC
[PATCH net] vhost: correctly remove wait queue during poll failure
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 checking poll->wqh to make sure it was in a list.
Reported-by: syzbot+c0272972b01b872e604a at syzkaller.appspotmail.com
Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting
backend")
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/vhost.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 1b3e8d2d..5d5a9d9 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -212,8 +212,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file
*file)
if (mask)
vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask));
if (mask & EPOLLERR) {
- if (poll->wqh)
- remove_wait_queue(poll->wqh, &poll->wait);
+ vhost_poll_stop(poll);
ret = -EINVAL;
}
--
2.7.4