From 4becb7ee5b3d2829ed7b9261a245a77d5b7de902 Mon Sep 17 00:00:00 2001 From: Xiyu Yang <xiyuyang19@fudan.edu.cn> Date: Sat, 25 Apr 2020 21:06:25 +0800 Subject: [PATCH] net/x25: Fix x25_neigh refcnt leak when x25 disconnect x25_connect() invokes x25_get_neigh(), which returns a reference of the specified x25_neigh object to "x25->neighbour" with increased refcnt. When x25 connect success and returns, the reference still be hold by "x25->neighbour", so the refcount should be decreased in x25_disconnect() to keep refcount balanced. The reference counting issue happens in x25_disconnect(), which forgets to decrease the refcnt increased by x25_get_neigh() in x25_connect(), causing a refcnt leak. Fix this issue by calling x25_neigh_put() before x25_disconnect() 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> --- net/x25/x25_subr.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c index 8aa415a38814b1..8b1b06cabcbfce 100644 --- a/net/x25/x25_subr.c +++ b/net/x25/x25_subr.c @@ -357,6 +357,10 @@ void x25_disconnect(struct sock *sk, int reason, unsigned char cause, sk->sk_state_change(sk); sock_set_flag(sk, SOCK_DEAD); } + read_lock_bh(&x25_list_lock); + x25_neigh_put(x25->neighbour); + x25->neighbour = NULL; + read_unlock_bh(&x25_list_lock); } /* -- GitLab