[PATCH v2,net-next 1/2] ip_gre: fix potential memory leak in erspan_rcv

If md is NULL, tun_dst must be freed, otherwise it will cause memory
leak.

Fixes: 1a66a836da6 ("gre: add collect_md mode to ERSPAN tunnel")
Cc: William Tu <redacted>
Signed-off-by: Haishuang Yan <redacted>

Change since v2:
  * Rebase on latest master branch.
  * Correct wrong fix information.
---
 net/ipv4/ip_gre.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 004800b..33af55a 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c

@@ -311,8 +311,10 @@ 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)
+			if (!md) {
+				dst_release((struct dst_entry *)tun_dst);
 				return PACKET_REJECT;
+			}
 
 			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;

-- 
1.8.3.1

If md is NULL, tun_dst must be freed, otherwise it will cause memory
leak.

Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Cc: William Tu <redacted>
Signed-off-by: Haishuang Yan <redacted>

Change since v2:
  * Rebase on latest master branch.
  * Correct wrong fix information.
---
 net/ipv6/ip6_gre.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 5c9c65f..8ce9d42 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c

@@ -549,8 +549,10 @@ 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)
+			if (!md) {
+				dst_release((struct dst_entry *)tun_dst);
 				return PACKET_REJECT;
+			}
 
 			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;

-- 
1.8.3.1

From: Haishuang Yan <redacted>
Date: Sat, 16 Dec 2017 10:48:38 +0800

If md is NULL, tun_dst must be freed, otherwise it will cause memory
leak.

Fixes: 1a66a836da6 ("gre: add collect_md mode to ERSPAN tunnel")
Cc: William Tu <redacted>
Signed-off-by: Haishuang Yan <redacted>

Change since v2:
  * Rebase on latest master branch.
  * Correct wrong fix information.

Please do not put a changelog after the fixes and signoff tags, those tags must
appear last in the commit message.

Thank you.

From: Haishuang Yan <redacted>
Date: Sat, 16 Dec 2017 10:48:39 +0800

If md is NULL, tun_dst must be freed, otherwise it will cause memory
leak.

Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Cc: William Tu <redacted>
Signed-off-by: Haishuang Yan <redacted>

Change since v2:
  * Rebase on latest master branch.
  * Correct wrong fix information.

Likewise, please place the tags at the end of the commit message.

On 2017年12月19日, at 下午11:36, David Miller [off-list ref] wrote:

From: Haishuang Yan <redacted>
Date: Sat, 16 Dec 2017 10:48:38 +0800

quoted

If md is NULL, tun_dst must be freed, otherwise it will cause memory
leak.

Fixes: 1a66a836da6 ("gre: add collect_md mode to ERSPAN tunnel")
Cc: William Tu <redacted>
Signed-off-by: Haishuang Yan <redacted>

Change since v2:
 * Rebase on latest master branch.
 * Correct wrong fix information.

Please do not put a changelog after the fixes and signoff tags, those tags must
appear last in the commit message.

Thank you.

Okay, I will resubmit another commit, thanks.