Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Thu, 7 Feb 2019 13:17:25 -0600
From: Timothy Michaud <tmm08a@....edu>
To: Ben Hutchings <ben.hutchings@...ethink.co.uk>
Cc: Yves-Alexis Perez <corsac@...ian.org>, oss-security@...ts.openwall.com
Subject: Re: Linux Kernel: Missing access_ok() checks in IOCTL function
 (gpu/drm/i915 Driver)

Hi Ben,

I believe you're correct. (grsecurity agrees with you for what it's worth).
I've emailed mitre but have not heard back yet.

Cheers,

Tim M.

On Thu, Feb 7, 2019 at 12:13 PM Ben Hutchings <ben.hutchings@...ethink.co.uk>
wrote:

> On Thu, 2019-01-24 at 10:30 +0100, Yves-Alexis Perez wrote:
> > On Wed, 2019-01-23 at 14:28 -0600, Timothy Michaud wrote:
> > > NOTE: I have requested a CVE identifier, and I'm sending this message,
> to
> > > make tracking of the fix easier; however, to avoid missing security
> fixes
> > > without CVE identifiers, you should *NOT* be cherry-picking a specific
> > > patch in response to a notification about a kernel security bug.
> > >
> > > Due to a lack of "access_ok()" checks in
> i915_gem_execbuffer2_ioctl[1], it
> > > is possible to escalate privileges similar to the waitid
> vulnerability[2]
> >
> > Hi, thanks for the report.
> >
> > The patch doesn't seem CC: stable, could you give us a status on the
> various
> > stable releases?
>
> Is there even a real security issue here?  So far as I can see,
> i915_gem_execbuffer2_ioctl() writes to a subset of the user memory
> range that it previously read using copy_from_user().  copy_from_user()
> does include the range check.
>
> Ben.
>
> --
> Ben Hutchings, Software Developer                         Codethink Ltd
> https://www.codethink.co.uk/                 Dale House, 35 Dale Street
>                                      Manchester, M1 2HF, United Kingdom
>

Powered by blists - more mailing lists

Your e-mail address:

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.