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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Thu, 18 Jan 2018 11:57:01 +0100
Message-ID: <CACT4Y+bodzr+URqDAXe_b+Rh4-bHFDmxSS0OTtSEUU0EOG+OvQ@mail.gmail.com>
Subject: Re: dangers of bots on the mailing lists was Re: divide error in ___bpf_prog_run
To:     Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc:     Pavel Machek <pavel@ucw.cz>,
        syzbot <syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>, syzkaller-bugs@googlegroups.com,
        "Theodore Ts'o" <tytso@mit.edu>
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On Wed, Jan 17, 2018 at 11:11 AM, Henrique de Moraes Holschuh
<hmh@hmh.eng.br> wrote:
> On Wed, 17 Jan 2018, Dmitry Vyukov wrote:
>> On Wed, Jan 17, 2018 at 10:32 AM, Pavel Machek <pavel@ucw.cz> wrote:
>> > On Fri 2018-01-12 17:58:01, syzbot wrote:
>> >> syzkaller hit the following crash on
>> >> 19d28fbd306e7ae7c1acf05c3e6968b56f0d196b
>> >
>> > What an useful way to describe kernel version.
>> >
>> > Could we get reasonable subject line? 4.15-rc7: prefix would be nice
>> > if it is on mainline,
>>
>> Yes, I guess. I am all for useful improvements.
>> What exactly is reasonable subject line? And how it can be extracted
>> for an arbitrary kernel tree?
>
> It can't, I guess.  But maybe you could extract it from syzbot
> information about the context of that patch?
>
> Maybe tagging it with the git tree you fetched when getting it over git,
> and mail from[1]+subject+message-id when getting it over email?
>
> [1] processing of related headers to handle mailing lists and
> retransmits is required, e.g. ressent-*, etc.  But this is relatively
> easy to do as well.
>
> A map to generate subject prefixes from key git trees or MLs could
> enhance that even further, to get at least mainline:, *-next:, etc.

Hi Henrique,

Re report format.

Ted also provided some useful feedback here:
https://groups.google.com/d/msg/syzkaller/5hjgr2v_oww/fn5QW6dvDQAJ

I've made a bunch of changes yesterday and today. This includes
rearranging lines in the email, rearranging attachment order, removing
some clutter, providing short repo alias (upstream, linux-next, net,
etc), providing commit date and title. syzbot will not also prefer to
report crashes on upstream tree, rather than on other trees.
Re subject line, I don't think prefixing subject with tree will work.
What you see as a single crash actually represents from tens to tens
of thousands crashes on some set of trees. And that set grows over
time. That can be one set of trees when the bug is first reported, and
then another subset of trees when a reproducer is found. It's
obviously a bad idea to send a email per crash (every few seconds),
and even per crash/tree. To alleviate this, syzbot will now say e.g.
"So far this crash happened 185 times on linux-next, mmots, net-next,
upstream". So that you can see that it's not only, say, linux-next
problem.

syzbot just mailed another report with all of these changes which you
can see here:
https://groups.google.com/forum/#!msg/syzkaller-bugs/u5nq3PdPkIc/F4tXzErxAgAJ

Thanks