Commit b0c64eda authored Oct 28, 2019 by Xin Long Committed by Greg Kroah-Hartman Nov 10, 2019

erspan: fix the tun_info options_len check for erspan



[ Upstream commit 2eb8d6d2910cfe3dc67dc056f26f3dd9c63d47cd ]

The check for !md doens't really work for ip_tunnel_info_opts(info) which
only does info + 1. Also to avoid out-of-bounds access on info, it should
ensure options_len is not less than erspan_metadata in both erspan_xmit()
and ip6erspan_tunnel_xmit().

Fixes: 1a66a836 ("gre: add collect_md mode to ERSPAN tunnel")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 41a230fe

net/ipv4/ip_gre.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -592,6 +592,9 @@ static void erspan_fb_xmit(struct sk_buff skb, struct net_device dev,
		truncate = true;
		}

		if (tun_info->options_len < sizeof(*md))
		goto err_free_rt;

		md = ip_tunnel_info_opts(tun_info);
		if (!md)
		goto err_free_rt;