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From: Gerd Hoffmann <kraxel@redhat.com>
To: David Buchanan <d@vidbuchanan.co.uk>, qemu-devel@nongnu.org
Cc: P J P <ppandit@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v2] vga: stop passing pointers to vga_draw_line* functions
Date: Mon, 09 Oct 2017 14:56:28 +0200	[thread overview]
Message-ID: <1507553788.32088.12.camel@redhat.com> (raw)
In-Reply-To: <e64a628c-3377-f3f5-0646-079a2a175354@vidbuchanan.co.uk>

On Mon, 2017-10-09 at 12:55 +0100, David Buchanan wrote:
> I might be mistaken, but I don't think this patch actually fixes
> CVE-2017-13672. I tested the latest git repo (last commit 530049bc1d)
> against my initial reproducer, and QEMU still segfaults.

Hmm, no segfault here.  Tried gtk, sdl, vnc, spice.  How do you start
qemu?  Which user interface?

> I think this is because the actual OOB read occurs inside pixman,
> which
> of course is not affected by this patch. Perhaps bounds checks need
> to
> be applied to the arguments passed into pixman?

Hmm, 24bpp modes are typically not handled by pixman (at least not in a
way that qemu creates a pixman image backed by vga memory).

Have you seen a stacktrace with pixman in there?  Care to share it?

thanks,
  Gerd

  reply	other threads:[~2017-10-09 12:56 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-28 12:29 [Qemu-devel] [PATCH v2] vga: stop passing pointers to vga_draw_line* functions Gerd Hoffmann
2017-10-09 11:55 ` David Buchanan
2017-10-09 12:56   ` Gerd Hoffmann [this message]
2017-10-09 13:09     ` David Buchanan

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