netdev - [PATCH net-next] lwtunnel: check erspan options before allocating tun

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-next>] [day] [month] [year] [list]

Message-Id: <b82b4b953ffc3a7053076bdfd20d5a62e07d5ad3.1574331290.git.lucien.xin@gmail.com>
Date:   Thu, 21 Nov 2019 18:14:50 +0800
From:   Xin Long <lucien.xin@...il.com>
To:     network dev <netdev@...r.kernel.org>
Cc:     davem@...emloft.net, simon.horman@...ronome.com,
        jakub.kicinski@...ronome.com
Subject: [PATCH net-next] lwtunnel: check erspan options before allocating tun_info

As Jakub suggested on another patch, it's better to do the check
on erspan options before allocating memory.

Signed-off-by: Xin Long <lucien.xin@...il.com>
---
 net/ipv4/ip_tunnel_core.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 0a7eaad..47f8b94 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -321,6 +321,7 @@ static int ip_tun_parse_opts_erspan(struct nlattr *attr,
 {
 	struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
 	int err;
+	u8 ver;
 
 	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr,
 			       erspan_opt_policy, extack);
@@ -330,24 +331,31 @@ static int ip_tun_parse_opts_erspan(struct nlattr *attr,
 	if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER])
 		return -EINVAL;
 
+	ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
+	if (ver == 1) {
+		if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX])
+			return -EINVAL;
+	} else if (ver == 2) {
+		if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] ||
+		    !tb[LWTUNNEL_IP_OPT_ERSPAN_HWID])
+			return -EINVAL;
+	} else {
+		return -EINVAL;
+	}
+
 	if (info) {
 		struct erspan_metadata *md =
 			ip_tunnel_info_opts(info) + opts_len;
 
-		attr = tb[LWTUNNEL_IP_OPT_ERSPAN_VER];
-		md->version = nla_get_u8(attr);
-
-		if (md->version == 1 && tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX]) {
+		md->version = ver;
+		if (ver == 1) {
 			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX];
 			md->u.index = nla_get_be32(attr);
-		} else if (md->version == 2 && tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] &&
-			   tb[LWTUNNEL_IP_OPT_ERSPAN_HWID]) {
+		} else {
 			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR];
 			md->u.md2.dir = nla_get_u8(attr);
 			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID];
 			set_hwid(&md->u.md2, nla_get_u8(attr));
-		} else {
-			return -EINVAL;
 		}
 
 		info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
-- 
2.1.0