linux-kernel - [PATCH 4.14 029/117] net: netrom: Fix potential nr_neigh refcnt leak in nr_add

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200501131548.323070885@linuxfoundation.org>
Date:   Fri,  1 May 2020 15:21:05 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Xiyu Yang <xiyuyang19@...an.edu.cn>,
        Xin Tan <tanxin.ctf@...il.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 4.14 029/117] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node

From: Xiyu Yang <xiyuyang19@...an.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@...an.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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);