2017-12-20 01:53:58

by Haishuang Yan

Subject: [PATCH v3,net-next] ip6_gre: fix a pontential issue in ip6erspan_rcv

pskb_may_pull() can change skb->data, so we need to load ipv6h/ershdr at
the right place.

Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support")
Cc: William Tu <[email protected]>
Acked-by: William Tu <[email protected]>
Signed-off-by: Haishuang Yan <[email protected]>

---
Change since v3:
* Rebase on latest master branch.
* Fix wrong commit information.
---
net/ipv6/ip6_gre.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 87b9892..9bd1103 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -507,12 +507,11 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
struct ip6_tnl *tunnel;
u8 ver;

- ipv6h = ipv6_hdr(skb);
- ershdr = (struct erspan_base_hdr *)skb->data;
-
if (unlikely(!pskb_may_pull(skb, sizeof(*ershdr))))
return PACKET_REJECT;

+ ipv6h = ipv6_hdr(skb);
+ ershdr = (struct erspan_base_hdr *)skb->data;
ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);

--
1.8.3.1

2017-12-20 18:52:50

by David Miller

Subject: Re: [PATCH v3,net-next] ip6_gre: fix a pontential issue in ip6erspan_rcv

From: Haishuang Yan <[email protected]>
Date: Wed, 20 Dec 2017 09:53:19 +0800

> pskb_may_pull() can change skb->data, so we need to load ipv6h/ershdr at
> the right place.
>
> Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support")
> Cc: William Tu <[email protected]>
> Acked-by: William Tu <[email protected]>
> Signed-off-by: Haishuang Yan <[email protected]>
>
> ---
> Change since v3:
> * Rebase on latest master branch.
> * Fix wrong commit information.

Applied.