Linux Kernel Mentees list
 help / color / mirror / Atom feed
From: Peilin Ye <yepeilin.cs@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: syzkaller-bugs@googlegroups.com, jslaby@suse.cz,
	linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
	linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [Linux-kernel-mentees] [PATCH 15/16] vc_screen: extract vcs_read_buf_header
Date: Tue, 25 Aug 2020 13:12:49 -0400	[thread overview]
Message-ID: <20200825171249.GA860904@PWN> (raw)
In-Reply-To: <20200825165935.GA1527003@kroah.com>

On Tue, Aug 25, 2020 at 06:59:35PM +0200, Greg KH wrote:
> On Tue, Aug 25, 2020 at 12:48:04PM -0400, Peilin Ye wrote:
> > Hi all,
> > 
> > Link: https://syzkaller.appspot.com/bug?id=f332576321998d36cd07d09c9c1268cfed1895c9
> > 
> > As reported by syzbot, vcs_read_buf() is overflowing `con_buf16`, since
> > this patch removed the following check:
> > 
> > -		if (count > CON_BUF_SIZE) {
> > -			count = CON_BUF_SIZE;
> > -			filled = count - pos;
> > -		}
> > 
> > Decreasing `count` by `min(HEADER_SIZE - pos, count)` bypasses this check.
> > Additionally, this patch also removed updates to `skip` and `filled`.
> > 
> > What should we do in order to fix it?
> 
> This patch is already reverted, and it has been discussed a bit as to
> how to do this properly if you look at the email where this was reported
> to us.

Ah, syzbot has reported this issue as two different bugs...I started
looking into it without noticing your discussion under another thread.

Sorry,
Peilin Ye
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

      reply	other threads:[~2020-08-25 17:13 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200818085706.12163-15-jslaby@suse.cz>
2020-08-25 16:48 ` [Linux-kernel-mentees] [PATCH 15/16] vc_screen: extract vcs_read_buf_header Peilin Ye
2020-08-25 16:59   ` Greg KH
2020-08-25 17:12     ` Peilin Ye [this message]

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=20200825171249.GA860904@PWN \
    --to=yepeilin.cs@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.cz \
    --cc=linux-kernel-mentees@lists.linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=syzkaller-bugs@googlegroups.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