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From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Fri, 9 Mar 2018 15:05:09 -0800
Message-ID: <CAM_iQpXLQtaBRBPmcGzUTUhNHiomos4eAvXy7kyrY+uAzpNt3g@mail.gmail.com>
Subject: Re: WARNING in __proc_create
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: syzbot <syzbot+0502b00edac2a0680b61@syzkaller.appspotmail.com>,
        coreteam@netfilter.org, David Miller <davem@davemloft.net>,
        Florian Westphal <fw@strlen.de>,
        Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        netfilter-devel@vger.kernel.org,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        syzkaller-bugs@googlegroups.com
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On Fri, Mar 9, 2018 at 2:58 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
>
> On 03/09/2018 02:56 PM, Eric Dumazet wrote:
>
>>
>> I sent a patch a while back, but Pablo/Florian wanted more than that
>> simple fix.
>>
>> We also need to filter special characters like '/'

proc_create_data() itself accepts '/', so it must be xt_hashlimit doesn't
want it.

>>
>> Or maybe I am mixing with something else.
>
>
> Yes, Florian mentioned that we also had to reject "."  and ".."
>

It could be, but looks like not as trivial as just strstr(".")?

BTW, the warning itself is all about empty names, so perhaps
it's better to fix them separately.