netdev - [PATCH 1/1] reset nf before xmit vxlan encapsulated packet

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-next>] [day] [month] [year] [list]

Message-Id: <1362413254-10520-1-git-send-email-zealot0630@gmail.com>
Date:	Tue,  5 Mar 2013 00:07:34 +0800
From:	Zang MingJie <zealot0630@...il.com>
To:	netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>
Cc:	Zang MingJie <zealot0630@...il.com>
Subject: [PATCH 1/1] reset nf before xmit vxlan encapsulated packet


We should reset nf settings bond to the skb as ipip/ipgre do.

If not, the conntrack/nat info bond to the origin packet may continually
redirect the packet to vxlan interface causing a routing loop.

this is the scenario:

     VETP     VXLAN Gateway
    /----\  /---------------\
    |    |  |               |
    |  vx+--+vx --NAT-> eth0+--> Internet
    |    |  |               |
    \----/  \---------------/

when there are any packet coming from internet to the vetp, there will be lots
of garbage packets coming out the gateway's vxlan interface, but none actually
sent to the physical interface, because they are redirected back to the vxlan
interface in the postrouting chain of NAT rule, and dmesg complains:

    Mar  1 21:52:53 debian kernel: [ 8802.997699] Dead loop on virtual device vxlan0, fix it urgently!
    Mar  1 21:52:54 debian kernel: [ 8804.004907] Dead loop on virtual device vxlan0, fix it urgently!
    Mar  1 21:52:55 debian kernel: [ 8805.012189] Dead loop on virtual device vxlan0, fix it urgently!
    Mar  1 21:52:56 debian kernel: [ 8806.020593] Dead loop on virtual device vxlan0, fix it urgently!

the patch should fix the problem

Signed-off-by: Zang MingJie <zealot0630@...il.com>
---
 drivers/net/vxlan.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index f10e58a..c3e3d29 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -961,6 +961,8 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 	iph->ttl	= ttl ? : ip4_dst_hoplimit(&rt->dst);
 	tunnel_ip_select_ident(skb, old_iph, &rt->dst);
 
+	nf_reset(skb);
+
 	vxlan_set_owner(dev, skb);
 
 	/* See iptunnel_xmit() */
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html