Re: 3.7.3+: Bad paging request in ip_rcv_finish while running NFS traffic.

[Eric Dumazet <eric.dumazet@gmail.com>]

On Mon, 2013-01-21 at 16:32 -0800, Ben Greear wrote:
> On 01/21/2013 01:07 PM, Ben Greear wrote:
> > I posted about this a few days ago, but this time the patches applied
> > are minimal and there are no out-of-tree kernel modules loaded.
> 
> Here's another crash, this time with SLUB memory debugging turned on.
> 
> Seems much harder to hit this way...I've only managed this one.  I
> believe the RCX register might be interesting...that 6b is probably
> freed memory poisioning.  Maybe skb or skb_dest() is already freed?
> 
> I have added a 'verify_mem_not_deleted(skb)' before the
> dst_input line in ip_rcv_finish..but so far, it hasn't
> hit the problem...
> 

There is no way skb is freed here.

I would say macvlan is at fault here.

It probably lacks a proper (dev->flags & IFF_UP) test.

Please try :

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index d3fb97d..c07bdef 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -111,9 +111,15 @@ static int macvlan_broadcast_one(struct sk_buff *skb,
 				 const struct ethhdr *eth, bool local)
 {
 	struct net_device *dev = vlan->dev;
+
 	if (!skb)
 		return NET_RX_DROP;
 
+	if (!(dev->flags & IFF_UP)) {
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
 	if (local)
 		return vlan->forward(dev, skb);