From: Xin Long <lucien.xin@xxxxxxxxx>
[ 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: 1a66a836da ("gre: add collect_md mode to ERSPAN tunnel")
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/ip_gre.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -592,6 +592,9 @@ static void erspan_fb_xmit(struct sk_buf
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;
