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 | 4 ++--
net/ipv6/ip6_gre.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -589,9 +589,9 @@ static void erspan_fb_xmit(struct sk_buf
key = &tun_info->key;
if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
goto err_free_rt;
+ if (tun_info->options_len < sizeof(*md))
+ goto err_free_rt;
md = ip_tunnel_info_opts(tun_info);
- if (!md)
- goto err_free_rt;
/* ERSPAN has fixed 8 byte GRE header */
version = md->version;
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1000,9 +1000,9 @@ static netdev_tx_t ip6erspan_tunnel_xmit
dsfield = key->tos;
if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
goto tx_err;
- md = ip_tunnel_info_opts(tun_info);
- if (!md)
+ if (tun_info->options_len < sizeof(*md))
goto tx_err;
+ md = ip_tunnel_info_opts(tun_info);
tun_id = tunnel_id_to_key32(key->tun_id);
if (md->version == 1) {
