Commit 4e48ed88 authored Aug 07, 2014 by Daniel Borkmann Committed by David S. Miller Aug 07, 2014

netlink: reset network header before passing to taps



netlink doesn't set any network header offset thus when the skb is
being passed to tap devices via dev_queue_xmit_nit(), it emits klog
false positives due to it being unset like:

  ...
  [  124.990397] protocol 0000 is buggy, dev nlmon0
  [  124.990411] protocol 0000 is buggy, dev nlmon0
  ...

So just reset the network header before passing to the device; for
packet sockets that just means nothing will change - mac and net
offset hold the same value just as before.

Reported-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 6f2c9bd8

net/netlink/af_netlink.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -213,7 +213,7 @@ static int __netlink_deliver_tap_skb(struct sk_buff *skb,
		nskb->protocol = htons((u16) sk->sk_protocol);
		nskb->pkt_type = netlink_is_kernel(sk) ?
		PACKET_KERNEL : PACKET_USER;

		skb_reset_network_header(nskb);
		ret = dev_queue_xmit(nskb);
		if (unlikely(ret > 0))
		ret = net_xmit_errno(ret);

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