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Date: Sat, 10 Mar 2018 00:18:59 +0100
From: Florian Westphal <fw@strlen.de>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
        syzbot <syzbot+0502b00edac2a0680b61@syzkaller.appspotmail.com>,
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        netfilter-devel@vger.kernel.org,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        syzkaller-bugs@googlegroups.com
Subject: Re: WARNING in __proc_create
Message-ID: <20180309231859.GA11882@breakpoint.cc>
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Cong Wang <xiyou.wangcong@gmail.com> wrote:
> 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.

--hashimit-name / also triggers WARN for me.
. or .. "work", (no crash), but cause appearance of 2nd ./.. in
/proc/net/ipt_hashlimit , so I think its better to disallow that too.