[PATCH net-next 0/2] net: erspan: a couple fixes

[PATCH net-next 0/2] net: erspan: a couple fixes

[William Tu]

Haishuang Yan reports a couple of issues (wrong return value, 
pskb_may_pull) on erspan V1.  Since erspan V2 is in net-next,
this series fix the similar issues on v2.

William Tu (2):
  net: erspan: fix wrong return value
  net: erspan: reload pointer after pskb_may_pull

 net/ipv4/ip_gre.c  | 6 ++++--
 net/ipv6/ip6_gre.c | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

-- 
2.7.4

[PATCH net-next 1/2] net: erspan: fix wrong return value

[William Tu]

If pskb_may_pull return failed, return PACKET_REJECT
instead of -ENOMEM.

Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support")
Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre")
Signed-off-by: William Tu <u9012063@gmail.com>
Cc: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
---
 net/ipv4/ip_gre.c  | 2 +-
 net/ipv6/ip6_gre.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 004800b923c6..1ca7451ff898 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -287,7 +287,7 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 	if (tunnel) {
 		len = gre_hdr_len + erspan_hdr_len(ver);
 		if (unlikely(!pskb_may_pull(skb, len)))
-			return -ENOMEM;
+			return PACKET_REJECT;
 
 		if (__iptunnel_pull_header(skb,
 					   len,
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 5c9c65f1d5c2..b3e4e0384f36 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -524,7 +524,7 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 		int len = erspan_hdr_len(ver);
 
 		if (unlikely(!pskb_may_pull(skb, len)))
-			return -ENOMEM;
+			return PACKET_REJECT;
 
 		if (__iptunnel_pull_header(skb, len,
 					   htons(ETH_P_TEB),
-- 
2.7.4

Re: [PATCH net-next 1/2] net: erspan: fix wrong return value

[严海双]

> On 2017年12月16日, at 上午6:27, William Tu <u9012063@gmail.com> wrote:
> 
> If pskb_may_pull return failed, return PACKET_REJECT
> instead of -ENOMEM.
> 
> Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support")
> Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre")
> Signed-off-by: William Tu <u9012063@gmail.com>
> Cc: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>

Acked-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>

[PATCH net-next 2/2] net: erspan: reload pointer after pskb_may_pull

[William Tu]

pskb_may_pull() can change skb->data, so we need to re-load pkt_md
and ershdr at the right place.

Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support")
Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre")
Signed-off-by: William Tu <u9012063@gmail.com>
Cc: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
---
 net/ipv4/ip_gre.c  | 4 +++-
 net/ipv6/ip6_gre.c | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 1ca7451ff898..02a34098afb0 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -279,7 +279,6 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 	 * Use ERSPAN 10-bit session ID as key.
 	 */
 	tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
-	pkt_md = (struct erspan_metadata *)(ershdr + 1);
 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
 				  tpi->flags | TUNNEL_KEY,
 				  iph->saddr, iph->daddr, tpi->key);
@@ -289,6 +288,9 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 		if (unlikely(!pskb_may_pull(skb, len)))
 			return PACKET_REJECT;
 
+		ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
+		pkt_md = (struct erspan_metadata *)(ershdr + 1);
+
 		if (__iptunnel_pull_header(skb,
 					   len,
 					   htons(ETH_P_TEB),
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index b3e4e0384f36..87b9892dfa23 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -515,7 +515,6 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 
 	ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
 	tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
-	pkt_md = (struct erspan_metadata *)(ershdr + 1);
 
 	tunnel = ip6gre_tunnel_lookup(skb->dev,
 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
@@ -526,6 +525,9 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 		if (unlikely(!pskb_may_pull(skb, len)))
 			return PACKET_REJECT;
 
+		ershdr = (struct erspan_base_hdr *)skb->data;
+		pkt_md = (struct erspan_metadata *)(ershdr + 1);
+
 		if (__iptunnel_pull_header(skb, len,
 					   htons(ETH_P_TEB),
 					   false, false) < 0)
-- 
2.7.4

Re: [PATCH net-next 0/2] net: erspan: a couple fixes

[David Miller]

From: William Tu <u9012063@gmail.com>
Date: Fri, 15 Dec 2017 14:27:42 -0800

> Haishuang Yan reports a couple of issues (wrong return value, 
> pskb_may_pull) on erspan V1.  Since erspan V2 is in net-next,
> this series fix the similar issues on v2.

Series applied, thank you.