From: Xiyu Yang Date: Sat, 25 Apr 2020 13:06:25 +0000 (+0800) Subject: net/x25: Fix x25_neigh refcnt leak when x25 disconnect X-Git-Tag: v4.14.192~26 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f0b6ce595c397a91d5b62c6b0b5ea93b84191795;p=users%2Fdwmw2%2Flinux.git 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 Signed-off-by: Xin Tan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c index db0b1315d577a..27c5885c14efd 100644 --- a/net/x25/x25_subr.c +++ b/net/x25/x25_subr.c @@ -363,6 +363,10 @@ 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); } /*