linux-serial.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
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: Fri, 13 Dec 2019 17:07:00 +0100	[thread overview]
Message-ID: <20191213160700.GA2632926@kroah.com> (raw)
In-Reply-To: <74859736-478a-6ad7-f0be-cfe87ec40ff5@i-love.sakura.ne.jp>

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.)

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.

thanks,

greg k-h

  reply	other threads:[~2019-12-13 21:49 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 [this message]
2019-12-14  0:48             ` Tetsuo Handa
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191213160700.GA2632926@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=asierra@xes-inc.com \
    --cc=dvyukov@google.com \
    --cc=ext-kimmo.rautkoski@vaisala.com \
    --cc=jslaby@suse.com \
    --cc=kai.heng.feng@canonical.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=o.barta89@gmail.com \
    --cc=paulburton@kernel.org \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    --cc=sr@denx.de \
    --cc=syzbot+f4f1e871965064ae689e@syzkaller.appspotmail.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=torvalds@linux-foundation.org \
    --cc=yegorslists@googlemail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).