From: Xiyu Yang Date: Wed, 15 Apr 2020 08:36:19 +0000 (+0800) Subject: net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node X-Git-Tag: v4.14.178~89 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b8a15c1b91bb2e1a7feafa7ce6b0db6a8b762179;p=thirdparty%2Fkernel%2Fstable.git net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node [ Upstream commit d03f228470a8c0a22b774d1f8d47071e0de4f6dd ] nr_add_node() invokes nr_neigh_get_dev(), which returns a local reference of the nr_neigh object to "nr_neigh" with increased refcnt. When nr_add_node() returns, "nr_neigh" becomes invalid, so the refcount should be decreased to keep refcount balanced. The issue happens in one normal path of nr_add_node(), which forgets to decrease the refcnt increased by nr_neigh_get_dev() and causes a refcnt leak. It should decrease the refcnt before the function returns like other normal paths do. Fix this issue by calling nr_neigh_put() before the nr_add_node() returns. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c index 0c59354e280ed..d098bb8d53aa4 100644 --- a/net/netrom/nr_route.c +++ b/net/netrom/nr_route.c @@ -199,6 +199,7 @@ static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic, /* refcount initialized at 1 */ spin_unlock_bh(&nr_node_list_lock); + nr_neigh_put(nr_neigh); return 0; } nr_node_lock(nr_node);