All of lore.kernel.org
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: Kyungtae Kim <kt0755@gmail.com>
Cc: w.d.hubbs@gmail.com, chris@the-brannons.com, kirk@reisers.ca,
	samuel.thibault@ens-lyon.org,
	Byoungyoung Lee <lifeasageek@gmail.com>,
	DaeRyong Jeong <threeearcat@gmail.com>,
	speakup@linux-speakup.org, devel@driverdev.osuosl.org,
	linux-kernel@vger.kernel.org, syzkaller@googlegroups.com
Subject: Re: general protection fault in spk_ttyio_ldisc_close
Date: Tue, 8 Jan 2019 14:50:20 +0100	[thread overview]
Message-ID: <20190108135020.GA10504@kroah.com> (raw)
In-Reply-To: <CAEAjamunJjFFJ8Yd-DQAv64MxYiiktsTUWex=boAOdc0+7h+uQ@mail.gmail.com>

On Tue, Jan 08, 2019 at 08:37:37AM -0500, Kyungtae Kim wrote:
> We report a bug in linux-4.20: "general protection fault in
> spk_ttyio_ldisc_close"
> 
> kernel config: https://kt0755.github.io/etc/config_v4.20_stable
> repro: https://kt0755.github.io/etc/repro.a670e.c
> 
> This occurs when the function kfree is about to execute
> (driver/staging/speakup/spk_ttyio.c:68).
> Particularly, kfree takes the argument like speakup_tty->disc_data.
> But speakup_tty is invalid, so the pointer dereference causes GPF.
> At a glance, it seems that speakup_tty was deallocated somewhere ahead of kfree.

How did you trigger this?  Did you shut down and close the device
already somehow?  Do you have a real tty device that is driven by the
device?

thanks,

greg k-h

  reply	other threads:[~2019-01-08 13:50 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-08 13:37 general protection fault in spk_ttyio_ldisc_close Kyungtae Kim
2019-01-08 13:50 ` Greg KH [this message]
2019-01-08 14:15   ` Kyungtae Kim
2019-01-08 14:25     ` Greg KH
2019-01-08 14:26       ` Samuel Thibault

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=20190108135020.GA10504@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=chris@the-brannons.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=kirk@reisers.ca \
    --cc=kt0755@gmail.com \
    --cc=lifeasageek@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=samuel.thibault@ens-lyon.org \
    --cc=speakup@linux-speakup.org \
    --cc=syzkaller@googlegroups.com \
    --cc=threeearcat@gmail.com \
    --cc=w.d.hubbs@gmail.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.