linux-kernel - [PATCH 3.2 093/110] inet: frags: fix defragmented packet's IP header for af

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <lsq.1439201551.431427637@decadent.org.uk>
Date:	Mon, 10 Aug 2015 12:12:31 +0200
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:	akpm@...ux-foundation.org, "Edward Hyunkoo Jee" <edjee@...gle.com>,
	"David S. Miller" <davem@...emloft.net>,
	"Jerry Chu" <hkchu@...gle.com>,
	"Eric Dumazet" <edumazet@...gle.com>,
	"Willem de Bruijn" <willemb@...gle.com>
Subject: [PATCH 3.2 093/110] inet: frags: fix defragmented packet's IP
 header for af_packet

3.2.71-rc1 review patch.  If anyone has any objections, please let me know.

------------------

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

commit 0848f6428ba3a2e42db124d41ac6f548655735bf upstream.

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@...gle.com>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: Willem de Bruijn <willemb@...gle.com>
Cc: Jerry Chu <hkchu@...gle.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 net/ipv4/ip_fragment.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -385,7 +385,7 @@ 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? */
@@ -415,7 +415,7 @@ static int ip_frag_queue(struct ipq *qp,
 		goto err;
 
 	err = -ENOMEM;
-	if (pskb_pull(skb, ihl) == NULL)
+	if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
 		goto err;
 
 	err = pskb_trim_rcsum(skb, end - offset);
@@ -638,6 +638,8 @@ static int ip_frag_reasm(struct ipq *qp,
 	iph->frag_off = 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;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/