Commit d94c1f92 authored Feb 07, 2014 by FX Le Bail Committed by David S. Miller Feb 09, 2014

ipv6: icmp6_send: fix Oops when pinging a not set up IPv6 peer on a sit tunnel



The patch 446fab59 ("ipv6: enable anycast addresses
as source addresses in ICMPv6 error messages") causes an Oops when pinging a not
set up IPv6 peer on a sit tunnel.

The problem is that ipv6_anycast_destination() uses unconditionally skb_dst(skb),
which is NULL in this case.

The solution is to use instead the ipv6_chk_acast_addr_src() function.

Here are the steps to reproduce it:
modprobe sit
ip link add sit1 type sit remote 10.16.0.121 local 10.16.0.249
ip l s sit1 up
ip -6 a a dev sit1 2001:1234::123 remote 2001:1234::121
ping6 2001:1234::121

Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Tested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Francois-Xavier Le Bail <fx.lebail@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e1d83ee6

net/ipv6/icmp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -414,7 +414,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
		addr_type = ipv6_addr_type(&hdr->daddr);

		if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) \|\|
		ipv6_anycast_destination(skb))
		ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
		saddr = &hdr->daddr;

		/*

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