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Subject: Re: net: heap out-of-bounds in
 fib6_clean_node/rt6_fill_node/fib6_age/fib6_prune_clone
To: Andrey Konovalov <andreyknvl@google.com>,
        Dmitry Vyukov <dvyukov@google.com>
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Cc: Eric Dumazet <eric.dumazet@gmail.com>,
        Mahesh Bandewar <maheshb@google.com>,
        Eric Dumazet <edumazet@google.com>, David 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>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        syzkaller <syzkaller@googlegroups.com>
From: David Ahern <dsa@cumulusnetworks.com>
Message-ID: <732d29dc-0240-cd1a-6973-5d14636ceaee@cumulusnetworks.com>
Date: Tue, 18 Apr 2017 17:20:27 -0600
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On 4/18/17 2:43 PM, Andrey Konovalov wrote:
> I've finally managed to reproduce one of the crashes on commit
> 4f7d029b9bf009fbee76bb10c0c4351a1870d2f3 (4.11-rc7).
> 
> I'm not sure if this bug has the same root cause as the first one
> reported in this thread, but it definitely has to do with ipv6
> routing.
> 
> C reproducer, syzkaller program and my .config are attached.
> 
> Thanks!
> 
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN
> Modules linked in:
> CPU: 1 PID: 4035 Comm: a.out Not tainted 4.11.0-rc7+ #250
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff880069809600 task.stack: ffff880062dc8000
> RIP: 0010:ip6_rt_cache_alloc+0xa6/0x560 net/ipv6/route.c:975

>>From a quick glance seems to be a different bug than Dmitry's.