diff options
author | Haishuang Yan <yanhaishuang@cmss.chinamobile.com> | 2016-04-03 22:09:24 +0800 |
---|---|---|
committer | Sasha Levin <sasha.levin@oracle.com> | 2016-07-10 23:07:07 -0400 |
commit | 1d8ad31a7ef1e1dcc4968518d5cefcd492bc2c58 (patch) | |
tree | 93bf396378c2a67f0b315cdc3a5be049c0b5b412 | |
parent | a9c5107769719e76a895fd59408442e5629fc40f (diff) |
ipv6: l2tp: fix a potential issue in l2tp_ip6_recv
[ Upstream commit be447f305494e019dfc37ea4cdf3b0e4200b4eba ]
pskb_may_pull() can change skb->data, so we have to load ptr/optr at the
right place.
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r-- | net/l2tp/l2tp_ip6.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c index 0ce9da948ad7..36f8fa223a78 100644 --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -135,12 +135,11 @@ static int l2tp_ip6_recv(struct sk_buff *skb) struct l2tp_tunnel *tunnel = NULL; int length; - /* Point to L2TP header */ - optr = ptr = skb->data; - if (!pskb_may_pull(skb, 4)) goto discard; + /* Point to L2TP header */ + optr = ptr = skb->data; session_id = ntohl(*((__be32 *) ptr)); ptr += 4; @@ -168,6 +167,9 @@ static int l2tp_ip6_recv(struct sk_buff *skb) if (!pskb_may_pull(skb, length)) goto discard; + /* Point to L2TP header */ + optr = ptr = skb->data; + ptr += 4; pr_debug("%s: ip recv\n", tunnel->name); print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); } |