Patch "inet: frags: fix defragmented packet's IP header for af_packet" has been added to the 4.1-stable tree

Patch "inet: frags: fix defragmented packet's IP header for af_packet" has been added to the 4.1-stable tree

[gregkh]

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

    inet: frags: fix defragmented packet's IP header for af_packet

to the 4.1-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:
     inet-frags-fix-defragmented-packet-s-ip-header-for-af_packet.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Sep 26 11:13:07 PDT 2015
From: Edward Hyunkoo Jee <edjee@google.com>
Date: Tue, 21 Jul 2015 09:43:59 +0200
Subject: inet: frags: fix defragmented packet's IP header for af_packet

From: Edward Hyunkoo Jee <edjee@google.com>

[ Upstream commit 0848f6428ba3a2e42db124d41ac6f548655735bf ]

When ip_frag_queue() computes positions, it assumes that the passed
sk_buff does not contain L2 headers.

However, when PACKET_FANOUT_FLAG_DEFRAG is used, IP reassembly
functions can be called on outgoing packets that contain L2 headers.

Also, IPv4 checksum is not corrected after reassembly.

Fixes: 7736d33f4262 ("packet: Add pre-defragmentation support for ipv4 fanouts.")
Signed-off-by: Edward Hyunkoo Jee <edjee@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/ip_fragment.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -342,7 +342,7 @@ static int ip_frag_queue(struct ipq *qp,
 	ihl = ip_hdrlen(skb);
 
 	/* Determine the position of this fragment. */
-	end = offset + skb->len - ihl;
+	end = offset + skb->len - skb_network_offset(skb) - ihl;
 	err = -EINVAL;
 
 	/* Is this the final fragment? */
@@ -372,7 +372,7 @@ static int ip_frag_queue(struct ipq *qp,
 		goto err;
 
 	err = -ENOMEM;
-	if (!pskb_pull(skb, ihl))
+	if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
 		goto err;
 
 	err = pskb_trim_rcsum(skb, end - offset);
@@ -613,6 +613,9 @@ static int ip_frag_reasm(struct ipq *qp,
 	iph->frag_off = qp->q.max_size ? htons(IP_DF) : 0;
 	iph->tot_len = htons(len);
 	iph->tos |= ecn;
+
+	ip_send_check(iph);
+
 	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
 	qp->q.fragments = NULL;
 	qp->q.fragments_tail = NULL;


Patches currently in stable-queue which might be from edjee@google.com are

queue-4.1/inet-frags-fix-defragmented-packet-s-ip-header-for-af_packet.patch