From: Andrey Konovalov <andreyknvl@google.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
James Morris <jmorris@namei.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Patrick McHardy <kaber@trash.net>,
netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Kostya Serebryany <kcc@google.com>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: net/ipv6: slab-out-of-bounds in ip6_tnl_xmit
Date: Tue, 25 Apr 2017 14:32:47 +0200 [thread overview]
Message-ID: <CAAeHK+z9B94iGJshTa7h++ZhS2BBqZD4GuyrNNp1awX=OKM5Tg@mail.gmail.com> (raw)
In-Reply-To: <CAM_iQpWnPgn0+-y34nGTB0byonLWCdf3_VAKcH8tK5fdzF4CBg@mail.gmail.com>
On Tue, Apr 25, 2017 at 7:04 AM, Cong Wang <xiyou.wangcong@gmail.com> wrote:
> On Mon, Apr 24, 2017 at 9:47 AM, Cong Wang <xiyou.wangcong@gmail.com> wrote:
>>
>> We use ipv4 dst in ip6_tunnel and cast an IPv4 neigh key as an
>> IPv6 address...
>>
>>
>> neigh = dst_neigh_lookup(skb_dst(skb),
>> &ipv6_hdr(skb)->daddr);
>> if (!neigh)
>> goto tx_err_link_failure;
>>
>> addr6 = (struct in6_addr *)&neigh->primary_key; // <=== HERE
>> addr_type = ipv6_addr_type(addr6);
>>
>> if (addr_type == IPV6_ADDR_ANY)
>> addr6 = &ipv6_hdr(skb)->daddr;
>>
>> memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
>>
>> Also the network header of the skb at this point should be still IPv4?
>
> Please try the attached patch.
I don't see these crashes with your patch.
Thanks!
Tested-by: Andrey Konovalov <andreyknvl@google.com>
>
> I am not sure how we could handle 4in6 case better than just relying on
> the config of ip6 tunnel.
prev parent reply other threads:[~2017-04-25 12:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-24 15:03 net/ipv6: slab-out-of-bounds in ip6_tnl_xmit Andrey Konovalov
2017-04-24 16:24 ` Andrey Konovalov
2017-04-24 16:47 ` Cong Wang
2017-04-25 5:04 ` Cong Wang
2017-04-25 12:32 ` Andrey Konovalov [this message]
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