| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 20/70] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node | Date | Fri, 1 May 2020 15:21:08 +0200 |
| |
From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
[ 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 <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/netrom/nr_route.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/netrom/nr_route.c +++ b/net/netrom/nr_route.c @@ -199,6 +199,7 @@ static int __must_check nr_add_node(ax25 /* refcount initialized at 1 */ spin_unlock_bh(&nr_node_list_lock); + nr_neigh_put(nr_neigh); return 0; } nr_node_lock(nr_node);
|