linux-kernel - [PATCH 3.2 060/147] l2tp: hold tunnel while processing genl delete command

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: <lsq.1510009387.860989343@decadent.org.uk>
Date:   Mon, 06 Nov 2017 23:03:07 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org,
        "Guillaume Nault" <g.nault@...halink.fr>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 3.2 060/147] l2tp: hold tunnel while processing genl
 delete command

3.2.95-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Guillaume Nault <g.nault@...halink.fr>

commit bb0a32ce4389e17e47e198d2cddaf141561581ad upstream.

l2tp_nl_cmd_tunnel_delete() needs to take a reference on the tunnel, to
prevent it from being concurrently freed by l2tp_tunnel_destruct().

Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@...halink.fr>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 net/l2tp/l2tp_netlink.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -184,14 +184,16 @@ static int l2tp_nl_cmd_tunnel_delete(str
 	}
 	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 
-	tunnel = l2tp_tunnel_find(net, tunnel_id);
-	if (tunnel == NULL) {
+	tunnel = l2tp_tunnel_get(net, tunnel_id);
+	if (!tunnel) {
 		ret = -ENODEV;
 		goto out;
 	}
 
 	(void) l2tp_tunnel_delete(tunnel);
 
+	l2tp_tunnel_dec_refcount(tunnel);
+
 out:
 	return ret;
 }