From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
syzbot <syzbot+f4f1e871965064ae689e@syzkaller.appspotmail.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
asierra@xes-inc.com, ext-kimmo.rautkoski@vaisala.com,
Jiri Slaby <jslaby@suse.com>,
kai heng feng <kai.heng.feng@canonical.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-serial <linux-serial@vger.kernel.org>,
mika.westerberg@linux.intel.com, o.barta89@gmail.com,
paulburton@kernel.org, sr@denx.de,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
yegorslists@googlemail.com
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in mem_serial_out
Date: Sat, 14 Dec 2019 09:48:29 +0900 [thread overview]
Message-ID: <4f514a5a-af11-e688-8f8d-72bbadadc889@i-love.sakura.ne.jp> (raw)
In-Reply-To: <20191213160700.GA2632926@kroah.com>
On 2019/12/14 1:07, Greg KH wrote:
> On Fri, Dec 13, 2019 at 11:31:08PM +0900, Tetsuo Handa wrote:
>> On 2019/12/13 19:00, Dmitry Vyukov wrote:
>>> Easier said than done. "normal user of the serial port" is not really
>>> a thing in Linux, right? You either have CAP_SYS_ADMIN or not, that's
>>> not per-device...
>>> As far as I remember +Tetsuo proposed a config along the lines of
>>> "restrict only things that legitimately cause damage under a fuzzer
>>> workload", e.g. freezing filesystems, disabling console output, etc.
>>> This may be another candidate. But I can't find where that proposal is
>>> now.
>>
>> That suggestion got no response for two months.
>>
>> https://lkml.kernel.org/r/3e4e2b6b-7828-54ab-cf28-db1a396d7e20@i-love.sakura.ne.jp
>>
>> Unless we add such kernel config option to upstream kernels, it will become
>> a whack-a-mole game.
>
> It will be a whack-a-mole game no matter what.
>
> Yes, /dev/mem/ makes no sense to fuzz. Neither does other things (like
> serial port memory addresses.)
/dev/mem makes sense to fuzz. Ditto for other things.
>
> You just will have a list of things that you "do not fuzz as these are
> dangerous". Nothing new here, any os will have that.
The list of kernel config options will become too complicated to maintain.
If we can have one kernel config option, we can avoid maintaining
the list of kernel config options (which keeps changing over time).
next prev parent reply other threads:[~2019-12-14 0:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-07 6:25 BUG: unable to handle kernel NULL pointer dereference in mem_serial_out syzbot
2019-12-12 10:57 ` Greg KH
2019-12-13 9:02 ` Dmitry Vyukov
2019-12-13 9:33 ` Greg KH
2019-12-13 10:00 ` Dmitry Vyukov
2019-12-13 10:10 ` Greg KH
2019-12-13 10:39 ` Dmitry Vyukov
2019-12-13 11:26 ` Greg KH
2019-12-17 10:48 ` Dmitry Vyukov
2020-01-07 17:02 ` Dmitry Vyukov
2019-12-13 14:31 ` Tetsuo Handa
2019-12-13 16:07 ` Greg KH
2019-12-14 0:48 ` Tetsuo Handa [this message]
2019-12-14 7:55 ` Greg KH
2019-12-14 8:39 ` Tetsuo Handa
2019-12-14 9:09 ` Greg KH
2019-12-14 10:28 ` Tetsuo Handa
2019-12-14 11:25 ` Greg KH
2019-12-18 0:55 ` Tetsuo Handa
2019-12-18 6:53 ` Dmitry Vyukov
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