netfilter: Pass socket pointer down through okfn().

On the output paths in particular, we have to sometimes deal with two
socket contexts.  First, and usually skb->sk, is the local socket that
generated the frame.

And second, is potentially the socket used to control a tunneling
socket, such as one the encapsulates using UDP.

We do not want to disassociate skb->sk when encapsulating in order
to fix this, because that would break socket memory accounting.

The most extreme case where this can cause huge problems is an
AF_PACKET socket transmitting over a vxlan device.  We hit code
paths doing checks that assume they are dealing with an ipv4
socket, but are actually operating upon the AF_PACKET one.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 7 deletions

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 052c5ebbc947..f921a5dce22d 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -55,8 +55,9 @@ static int br_pass_frame_up(struct sk_buff *skb)
         if (!skb)
                 return NET_RX_DROP;
 
-        return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
-                       netif_receive_skb);
+        return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, NULL, skb,
+                       indev, NULL,
+                       netif_receive_skb_sk);
 }
 
 static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
@@ -119,7 +120,7 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
 }
 
 /* note: already called with rcu_read_lock */
-int br_handle_frame_finish(struct sk_buff *skb)
+int br_handle_frame_finish(struct sock *sk, struct sk_buff *skb)
 {
         const unsigned char *dest = eth_hdr(skb)->h_dest;
         struct net_bridge_port *p = br_port_get_rcu(skb->dev);
@@ -207,7 +208,7 @@ drop:
 EXPORT_SYMBOL_GPL(br_handle_frame_finish);
 
 /* note: already called with rcu_read_lock */
-static int br_handle_local_finish(struct sk_buff *skb)
+static int br_handle_local_finish(struct sock *sk, struct sk_buff *skb)
 {
         struct net_bridge_port *p = br_port_get_rcu(skb->dev);
         u16 vid = 0;
@@ -277,8 +278,8 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
                 }
 
                 /* Deliver packet to local host only */
-                if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
-                            NULL, br_handle_local_finish)) {
+                if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, NULL, skb,
+                            skb->dev, NULL, br_handle_local_finish)) {
                         return RX_HANDLER_CONSUMED; /* consumed by filter */
                 } else {
                         *pskb = skb;
@@ -302,7 +303,8 @@ forward:
                 if (ether_addr_equal(p->br->dev->dev_addr, dest))
                         skb->pkt_type = PACKET_HOST;
 
-                NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
+                NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, NULL, skb,
+                        skb->dev, NULL,
                         br_handle_frame_finish);
                 break;
         default: