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Subject: Re: [ldv-project] [PATCH v2] drm/fb-helper: add virtual screen size
 check to drm_fb_helper_check_var()
To:     Geert Uytterhoeven <geert@linux-m68k.org>,
        Andrey Strachuk <strochuk@ispras.ru>
Cc:     ldv-project@linuxtesting.org,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@linux.ie>, Helge Deller <deller@gmx.de>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Maxime Ripard <mripard@kernel.org>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Daniel Vetter <daniel@ffwll.ch>
References: <20220811144850.215377-1-strochuk@ispras.ru>
 <CAMuHMdXSnHJpy=27pkAfQC0v+tkpx7Q4Ze1=nvTmy+aMBeVPFg@mail.gmail.com>
From:   Alexey Khoroshilov <khoroshilov@ispras.ru>
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Message-ID: <da72ac1b-57ef-18c5-98c7-f6f1a4c11b8d@ispras.ru>
Date:   Thu, 11 Aug 2022 23:59:00 +0300
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For v2 I would suggest to update description to something like this:

Make sure that virtual screen size is not less than physical screen one.

and comment to:
    /* make sure that virtual resolution >= physical resolution */

--
Alexey


On 11.08.2022 17:54, Geert Uytterhoeven wrote:
> Hi Andrey,
> 
> On Thu, Aug 11, 2022 at 4:49 PM Andrey Strachuk <strochuk@ispras.ru> wrote:
>> Add virtual screen size check to drm_fb_helper_check_var() in
>> order to validate userspace input.
>>
>> Found by Linux Verification Center (linuxtesting.org) with syzkaller.
>>
>> Signed-off-by: Andrey Strachuk <strochuk@ispras.ru>
> 
> Thanks for the update!
> 
>> Fixes: 785b93ef8c30 ("drm/kms: move driver specific fb common code to helper functions (v2)")
> 
> I'd drop the Fixes tag completely, as the bug was present in the
> intel and radeon drivers before. But probably it doesn't matter, as no one
> is gonna backport this to v2.6.31 and earlier ;-)
> 
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
> 
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