[PATCH 3.13 008/212] bridge: Fix double free and memory leak around br_allowed_ingress

Kamal Mostafa
2014-06-17T21:41:42Z

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: Kamal Mostafa <kamal@canonical.com>
---
net/bridge/br_input.c | 2 +-
net/bridge/br_vlan.c | 7 ++++---
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 7e73c32..fa29179 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -72,7 +72,7 @@ int br_handle_frame_finish(struct sk_buff *skb)
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;
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index af5ebd1..9bddc9b 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -193,7 +193,7 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
* rejected.
*/
if (!v)
- return false;
+ goto drop;

err = br_vlan_get_tag(skb, vid);
if (!*vid) {
@@ -204,7 +204,7 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
* vlan untagged or priority-tagged traffic belongs to.
*/
if (pvid == VLAN_N_VID)
- return false;
+ goto drop;

/* PVID is set on this port. Any untagged or priority-tagged
* ingress frame is considered to belong to this vlan.
@@ -227,7 +227,8 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
/* 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;
}

--
1.9.1