[PATCH 3.15 041/109] 8021q: fix a potential memory leak

Greg Kroah-Hartman
2014-07-26T19:02:03Z

From: Li RongQing <roy.qing.li@gmail.com>

[ Upstream commit 916c1689a09bc1ca81f2d7a34876f8d35aadd11b ]

skb_cow called in vlan_reorder_header does not free the skb when it failed,
and vlan_reorder_header returns NULL to reset original skb when it is called
in vlan_untag, lead to a memory leak.

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/8021q/vlan_core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -114,8 +114,11 @@ EXPORT_SYMBOL(vlan_dev_vlan_proto);

static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
{
- if (skb_cow(skb, skb_headroom(skb)) < 0)
+ if (skb_cow(skb, skb_headroom(skb)) < 0) {
+ kfree_skb(skb);
return NULL;
+ }
+
memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
skb->mac_header += VLAN_HLEN;
return skb;