[PATCH v3,net-next 0/2] net: erspan: fix potential memory leak

This patch series fix potential memory leak issue.

Haishuang Yan (2):
  ip_gre: fix potential memory leak in erspan_rcv
  ip6_gre: fix potential memory leak in ip6erspan_rcv

 net/ipv4/ip_gre.c  | 4 +++-
 net/ipv6/ip6_gre.c | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

--
1.8.3.1

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>

---
Changes since v3:
  * Rebase on latest master branch.
  * Fix wrong commit 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 fd4d6e9..3029e3e 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c

@@ -313,8 +313,10 @@ 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>

---
Changes since v3:
  * Rebase on latest master branch.
  * Fix wrong commit 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 9bd1103..45038a9 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c

@@ -550,8 +550,10 @@ 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

On Tue, Dec 19, 2017 at 6:07 PM, Haishuang Yan
[off-list ref] wrote:

isn't md allocated previously at
    tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
                                           sizeof(*md));
so md should never be null after we check tun_dst?
William

From: Haishuang Yan <redacted>
Date: Wed, 20 Dec 2017 10:07:00 +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>

Applied.

From: Haishuang Yan <redacted>
Date: Wed, 20 Dec 2017 10:07:01 +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>

Applied.

I agree with William that 'md' should never be NULL here, but that check existing
before your changes so removing it is a separate patch altogether.