| From 7a339f13cf53690e20249d9d939b6cdaa8965153 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 |
| |
| commit 4becb7ee5b3d2829ed7b9261a245a77d5b7de902 upstream. |
| |
| 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> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c |
| index 8aa415a38814..8b1b06cabcbf 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); |
| } |
| |
| /* |
| -- |
| 2.27.0 |
| |
