[PATCH net 2/5] l2tp: hold tunnel while processing genl delete command

[Guillaume Nault]

l2tp_nl_cmd_tunnel_delete() needs to take a reference on the tunnel, to
prevent it from being concurrently freed by l2tp_tunnel_destruct().

Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.na...@alphalink.fr>
---
 net/l2tp/l2tp_netlink.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 27ee94b5c189..808966550620 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -273,8 +273,8 @@ static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, 
struct genl_info *info
        }
        tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 
-       tunnel = l2tp_tunnel_find(net, tunnel_id);
-       if (tunnel == NULL) {
+       tunnel = l2tp_tunnel_get(net, tunnel_id);
+       if (!tunnel) {
                ret = -ENODEV;
                goto out;
        }
@@ -284,6 +284,8 @@ static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, 
struct genl_info *info
 
        (void) l2tp_tunnel_delete(tunnel);
 
+       l2tp_tunnel_dec_refcount(tunnel);
+
 out:
        return ret;
 }
-- 
2.14.1