[PATCH net-next] net: erspan: remove md NULL check

[PATCH net-next] net: erspan: remove md NULL check

[William Tu]

The 'md' is allocated from 'tun_dst = ip_tun_rx_dst' and
since we've checked 'tun_dst', 'md' will never be NULL.
The patch removes it at both ipv4 and ipv6 erspan.

Fixes: afb4c97d90e6 ("ip6_gre: fix potential memory leak in ip6erspan_rcv")
Fixes: 50670b6ee9bc ("ip_gre: fix potential memory leak in erspan_rcv")
Cc: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: William Tu <u9012063@gmail.com>
---
 net/ipv4/ip_gre.c  | 5 -----
 net/ipv6/ip6_gre.c | 4 ----
 2 files changed, 9 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 90c912307814..47c7de3ca458 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -313,11 +313,6 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 				return PACKET_REJECT;
 
 			md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
-			if (!md) {
-				dst_release((struct dst_entry *)tun_dst);
-				return PACKET_REJECT;
-			}
-
 			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;
 
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 8451d00b210b..1aabc8df7cb7 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -550,10 +550,6 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 
 			info = &tun_dst->u.tun_info;
 			md = ip_tunnel_info_opts(info);
-			if (!md) {
-				dst_release((struct dst_entry *)tun_dst);
-				return PACKET_REJECT;
-			}
 
 			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;
-- 
2.7.4

Re: [PATCH net-next] net: erspan: remove md NULL check

[David Miller]

From: William Tu <u9012063@gmail.com>
Date: Thu, 21 Dec 2017 15:51:22 -0800

> The 'md' is allocated from 'tun_dst = ip_tun_rx_dst' and
> since we've checked 'tun_dst', 'md' will never be NULL.
> The patch removes it at both ipv4 and ipv6 erspan.
> 
> Fixes: afb4c97d90e6 ("ip6_gre: fix potential memory leak in ip6erspan_rcv")
> Fixes: 50670b6ee9bc ("ip_gre: fix potential memory leak in erspan_rcv")
> Cc: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
> Signed-off-by: William Tu <u9012063@gmail.com>

Applied.