Patch "packet: do skb_probe_transport_header when we actually have data" has been added to the 4.3-stable tree

This is a note to let you know that I've just added the patch titled

packet: do skb_probe_transport_header when we actually have data

to the 4.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
packet-do-skb_probe_transport_header-when-we-actually-have-data.patch
and it can be found in the queue-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Daniel Borkmann <[email protected]>
Date: Wed, 11 Nov 2015 23:25:40 +0100
Subject: packet: do skb_probe_transport_header when we actually have data

From: Daniel Borkmann <[email protected]>

[ Upstream commit efdfa2f7848f64517008136fb41f53c4a1faf93a ]

In tpacket_fill_skb() commit c1aad275b029 ("packet: set transport header before doing xmit") and later on 40893fd0fd4e ("net: switch to use skb_probe_transport_header()") was probing for a transport header on the skb from a ring buffer slot, but at a time, where the skb has _not even_ been filled with data yet. So that call into the flow dissector is pretty useless. Lets do it after we've set up the skb frags.

---
 net/packet/af_packet.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -2368,8 +2368,6 @@ static int tpacket_fill_skb(struct packe
 	skb_reserve(skb, hlen);
 	skb_reset_network_header(skb);
 
-	if (!packet_use_direct_xmit(po))
-		skb_probe_transport_header(skb, 0);
 	if (unlikely(po->tp_tx_has_off)) {
 		int off_min, off_max, off;
 		off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);

@@ -2449,6 +2447,9 @@ static int tpacket_fill_skb(struct packe
 		len = ((to_write > len_max) ? len_max : to_write);
 	}
 
+	if (!packet_use_direct_xmit(po))
+		skb_probe_transport_header(skb, 0);
+
 	return tp_len;
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.3/packet-infer-protocol-from-ethernet-header-if-unset.patch queue-4.3/bpf-array-fix-heap-out-of-bounds-access-when-updating-elements.patch queue-4.3/ipv6-sctp-implement-sctp_v6_destroy_sock.patch queue-4.3/packet-only-allow-extra-vlan-len-on-ethernet-devices.patch queue-4.3/net-scm-fix-pax-detected-msg_controllen-overflow-in-scm_detach_fds.patch queue-4.3/packet-fix-tpacket_snd-max-frame-len.patch queue-4.3/packet-always-probe-for-transport-header.patch queue-4.3/packet-do-skb_probe_transport_header-when-we-actually-have-data.patch queue-4.3/tools-net-use-include-uapi-with-__exported_headers__.patch