diff options
authorEric Dumazet <edumazet@google.com>2013-06-26 04:15:07 -0700
committerDavid S. Miller <davem@davemloft.net>2013-06-26 15:13:47 -0700
commita963a37d384d71ad43b3e9e79d68d42fbe0901f3 (patch)
parent5dbe7c178d3f0a4634f088d9e729f1909b9ddcd1 (diff)
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>
1 files changed, 7 insertions, 1 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 95703ba2c084..d5d20cde8d92 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -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,