bridge: Fix double free and memory leak around br_allowed_ingress

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>

2 files changed, 5 insertions, 4 deletions

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index d0cca3c65f01..7985deaff52f 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -73,7 +73,7 @@ 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 91510712c7a7..4a3716102789 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -170,7 +170,7 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
          * rejected.
          */
         if (!v)
-                return false;
+                goto drop;
 
         /* If vlan tx offload is disabled on bridge device and frame was
          * sent from vlan device on the bridge device, it does not have
@@ -193,7 +193,7 @@ 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.
@@ -216,7 +216,8 @@ 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;
 }