From 2eb8d6d2910cfe3dc67dc056f26f3dd9c63d47cd Mon Sep 17 00:00:00 2001 From: Xin Long Date: Mon, 28 Oct 2019 23:19:35 +0800 Subject: erspan: fix the tun_info options_len check for erspan 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: 1a66a836da ("gre: add collect_md mode to ERSPAN tunnel") Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4/ip_gre.c') diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 52690bb3e40f..10636fb6093e 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -509,9 +509,9 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) key = &tun_info->key; if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) goto err_free_skb; - md = ip_tunnel_info_opts(tun_info); - if (!md) + if (tun_info->options_len < sizeof(*md)) goto err_free_skb; + md = ip_tunnel_info_opts(tun_info); /* ERSPAN has fixed 8 byte GRE header */ version = md->version; -- cgit v1.2.3