l2tp: take a reference for kernel sockets in l2tp_tunnel_sock_lookup

When looking up the tunnel socket in struct l2tp_tunnel, hold a reference
whether the socket was created by the kernel or by userspace.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 0dd50c079f29..45373fee38c5 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -191,6 +191,7 @@ struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel)
         } else {
                 /* Socket is owned by kernelspace */
                 sk = tunnel->sock;
+                sock_hold(sk);
         }
 
 out:
@@ -209,6 +210,7 @@ void l2tp_tunnel_sock_put(struct sock *sk)
                 }
                 sock_put(sk);
         }
+        sock_put(sk);
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_put);