diff options
| author | Haishuang Yan <yanhaishuang@cmss.chinamobile.com> | 2016-04-03 22:09:23 +0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-05-01 00:05:27 +0200 |
| commit | f56bbe05031ec62fed752671fdf510cc202b67cf (patch) | |
| tree | b5190ff5260eff1bac6f8a5d215392c4c5d370de | |
| parent | 8b59e5023e8255a91418bd7831b5ef03621499d5 (diff) | |
ipv4: l2tp: fix a potential issue in l2tp_ip_recv
[ Upstream commit 5745b8232e942abd5e16e85fa9b27cc21324acf0 ]
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | net/l2tp/l2tp_ip.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 334a93d1a8ed..2d9b98ecbd73 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -129,12 +129,11 @@ static int l2tp_ip_recv(struct sk_buff *skb) int length; int offset; - /* 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; @@ -162,6 +161,9 @@ static int l2tp_ip_recv(struct sk_buff *skb) if (!pskb_may_pull(skb, length)) goto discard; + /* Point to L2TP header */ + optr = ptr = skb->data; + ptr += 4; printk(KERN_DEBUG "%s: ip recv: ", tunnel->name); offset = 0; |