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Subject: Re: KASAN: use-after-free Read in skb_ensure_writable
To:     syzbot <syzbot+c8504affd4fdd0c1b626@syzkaller.appspotmail.com>,
        ast@kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com
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From:   Daniel Borkmann <daniel@iogearbox.net>
Message-ID: <d3027a7d-f903-16ee-24c6-81689a1ed886@iogearbox.net>
Date:   Fri, 8 Jun 2018 11:53:13 +0200
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On 06/04/2018 01:36 AM, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    bcece5dc40b9 bpf: Change bpf_fib_lookup to return -EAFNOSU..
> git tree:       bpf-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=10ee76b7800000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e4078980b886800c
> dashboard link: https://syzkaller.appspot.com/bug?extid=c8504affd4fdd0c1b626
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=10d926df800000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1778c26f800000

#syz fix: bpf: reject passing modified ctx to helper functions