[PATCH 3.11 100/138] bridge: Fix double free and memory leak around br_allowed_ingress

From: Luis Henriques
Date: Tue Jun 03 2014 - 07:55:39 EST


3.11.10.11 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Toshiaki Makita <makita.toshiaki@xxxxxxxxxxxxx>

commit eb7076182d1ae4bc4641534134ed707100d76acc upstream.

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@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
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 a2fd37ec35f7..c378750602cd 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 9a9ffe7e4019..d8deb8bda736 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -202,7 +202,7 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
* 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_bridge *br, struct net_port_vlans *v,
* 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_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

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