diff options
author | Haishuang Yan <yanhaishuang@cmss.chinamobile.com> | 2016-04-03 22:09:23 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-20 15:45:17 +0900 |
commit | 169af15e93de7974ca3a5ff9b7149034fae96bfc (patch) | |
tree | 98d99d5aaa796025dd7a33c6b9992aaf19ffa771 /net | |
parent | 502ef3a17da463efe3ab31646db5cf5f52b120be (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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-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 ec22078b0914..42de4ccd159f 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -123,12 +123,11 @@ static int l2tp_ip_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; @@ -156,6 +155,9 @@ 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; pr_debug("%s: ip recv\n", tunnel->name); print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); } |