From: Daniel Borkmann Date: Thu, 7 Aug 2014 20:22:47 +0000 (+0200) Subject: netlink: reset network header before passing to taps X-Git-Tag: v3.14.22~37 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5c2f8986e4b03cad626e40caf9f93aedbef7254;p=thirdparty%2Fkernel%2Fstable.git netlink: reset network header before passing to taps [ Upstream commit 4e48ed883c72e78c5a910f8831ffe90c9b18f0ec ] 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 Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 0dfe894afd485..c375d731587fe 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -205,7 +205,7 @@ 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);