| From | Kamal Mostafa <> | Subject | [PATCH 50/75] ipv6: ip6_sk_dst_check() must not assume ipv6 dst | Date | Tue, 30 Jul 2013 11:44:54 -0700 |
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3.8.13.6 -stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ Upstream commit a963a37d384d71ad43b3e9e79d68d42fbe0901f3 ]
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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/ipv6/ip6_output.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 2adff32..978e4a3 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -843,11 +843,17 @@ 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, -- 1.8.1.2
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