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Commit 0848f642 authored by Edward Hyunkoo Jee's avatar Edward Hyunkoo Jee Committed by David S. Miller
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inet: frags: fix defragmented packet's IP header for af_packet 



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: 7736d33f ("packet: Add pre-defragmentation support for ipv4 fanouts.")
Signed-off-by: default avatarEdward Hyunkoo Jee <edjee@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a84e3289

net/ipv4/ip_fragment.c

+4 −2
Original line number Diff line number Diff line
@@ -351,7 +351,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) 
	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? */
@@ -381,7 +381,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) 
		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);
@@ -641,6 +641,8 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 
		iph->frag_off = 0;

	}



	ip_send_check(iph);



	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);

	qp->q.fragments = NULL;

	qp->q.fragments_tail = NULL;