[PATCH 3.10 44/86] bridge: Fix double free and memory leak around br_allowed_ingress

Greg Kroah-Hartman
2014-05-29T04:55:22Z

From: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>

[ Upstream commit eb7076182d1ae4bc4641534134ed707100d76acc ]

br_allowed_ingress() has two problems.

1. If br_allowed_ingress() is called by br_handle_frame_finish() and
vlan_untag() in br_allowed_ingress() fails, skb will be freed by both
vlan_untag() and br_handle_frame_finish().

2. If br_allowed_ingress() is called by br_dev_xmit() and
br_allowed_ingress() fails, the skb will not be freed.

Fix these two problems by freeing the skb in br_allowed_ingress()
if it fails.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/br_input.c | 2 +-
net/bridge/br_vlan.c | 7 ++++---
2 files changed, 5 insertions(+), 4 deletions(-)

--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -71,7 +71,7 @@ int br_handle_frame_finish(struct sk_buf
goto drop;

if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb, &vid))
- goto drop;
+ goto out;

/* insert into forwarding database after filtering to avoid spoofing */
br = p->br;
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -202,7 +202,7 @@ bool br_allowed_ingress(struct net_bridg
* rejected.
*/
if (!v)
- return false;
+ goto drop;

if (br_vlan_get_tag(skb, vid)) {
u16 pvid = br_get_pvid(v);
@@ -212,7 +212,7 @@ bool br_allowed_ingress(struct net_bridg
* traffic belongs to.
*/
if (pvid == VLAN_N_VID)
- return false;
+ goto drop;

/* PVID is set on this port. Any untagged ingress
* frame is considered to belong to this vlan.
@@ -224,7 +224,8 @@ bool br_allowed_ingress(struct net_bridg
/* Frame had a valid vlan tag. See if vlan is allowed */
if (test_bit(*vid, v->vlan_bitmap))
return true;
-
+drop:
+ kfree_skb(skb);
return false;
}