Commit a963a37d authored Jun 26, 2013 by Eric Dumazet Committed by David S. Miller Jun 26, 2013

ipv6: ip6_sk_dst_check() must not assume ipv6 dst



It's possible to use AF_INET6 sockets and to connect to an IPv4
destination. After this, socket dst cache is a pointer to a rtable,
not rt6_info.

ip6_sk_dst_check() should check the socket dst cache is IPv6, or else
various corruptions/crashes can happen.

Dave Jones can reproduce immediate crash with
trinity -q -l off -n -c sendmsg -c connect

With help from Hannes Frederic Sowa

Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5dbe7c17

net/ipv6/ip6_output.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -821,11 +821,17 @@ static struct dst_entry ip6_sk_dst_check(struct sock sk,
		const struct flowi6 *fl6)
		{
		struct ipv6_pinfo *np = inet6_sk(sk);
		struct rt6_info rt = (struct rt6_info )dst;
		struct rt6_info *rt;

		if (!dst)
		goto out;

		if (dst->ops->family != AF_INET6) {
		dst_release(dst);
		return NULL;
		}

		rt = (struct rt6_info *)dst;
		/* Yes, checking route validity in not connected
		* case is not very simple. Take into account,
		* that we do not support routing by source, TOS,

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