[PATCH 4.9 16/56] tun: add a missing rcu_read_unlock() in error path

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <eduma...@google.com>

commit 9180bb4f046064dfa4541488102703b402bb04e1 upstream.

In my latest patch I missed one rcu_read_unlock(), in case
device is down.

Fixes: 4477138fa0ae ("tun: properly test for IFF_UP")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: syzbot <syzkal...@googlegroups.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/net/tun.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1330,6 +1330,7 @@ drop:
        rcu_read_lock();
        if (unlikely(!(tun->dev->flags & IFF_UP))) {
                err = -EIO;
+               rcu_read_unlock();
                goto drop;
        }