From: Guillaume Nault g.nault@alphalink.fr
commit 8c0e421525c9eb50d68e8f633f703ca31680b746 upstream.
We need to make sure the tunnel is not going to be destroyed by l2tp_tunnel_destruct() concurrently.
Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault g.nault@alphalink.fr Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Giuliano Procida gprocida@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/l2tp/l2tp_netlink.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -310,8 +310,8 @@ static int l2tp_nl_cmd_tunnel_modify(str } 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; } @@ -322,6 +322,8 @@ static int l2tp_nl_cmd_tunnel_modify(str ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel, L2TP_CMD_TUNNEL_MODIFY);
+ l2tp_tunnel_dec_refcount(tunnel); + out: return ret; }