Hi, 

> -----Original Message-----
> From: Saarinen, Jani
> Sent: Monday, 1 June 2026 22.24
> To: 'Thomas Zimmermann' <[email protected]>; Jani Nikula
> <[email protected]>; Dave Airlie <[email protected]>; Simona
> Vetter <[email protected]>
> Cc: Joonas Lahtinen <[email protected]>; Tvrtko Ursulin
> <[email protected]>; Vivi, Rodrigo <[email protected]>; Maarten
> Lankhorst <[email protected]>; Maxime Ripard
> <[email protected]>; Brost, Matthew <[email protected]>; Thomas
> Hellström <[email protected]>; Oded Gabbay
> <[email protected]>; [email protected]; intel-
> [email protected]; [email protected]; dim-
> [email protected]
> Subject: RE: [PULL] drm-misc-fixes
> 
> Hi,
> > -----Original Message-----
> > From: Intel-gfx <[email protected]> On Behalf Of
> > Thomas Zimmermann
> > Sent: Monday, 1 June 2026 20.27
> > To: Jani Nikula <[email protected]>; Dave Airlie
> > <[email protected]>; Simona Vetter <[email protected]>
> > Cc: Joonas Lahtinen <[email protected]>; Tvrtko Ursulin
> > <[email protected]>; Vivi, Rodrigo <[email protected]>;
> > Maarten Lankhorst <[email protected]>; Maxime Ripard
> > <[email protected]>; Brost, Matthew <[email protected]>;
> Thomas
> > Hellström <[email protected]>; Oded Gabbay
> > <[email protected]>; [email protected]; intel-
> > [email protected]; [email protected]; dim-
> > [email protected]
> > Subject: Re: [PULL] drm-misc-fixes
> >
> > Hi
> >
> > Am 01.06.26 um 17:49 schrieb Jani Nikula:
> > > On Mon, 01 Jun 2026, Jani Nikula <[email protected]> wrote:
> > >> On Mon, 01 Jun 2026, Jani Nikula <[email protected]> wrote:
> > >>> On Fri, 29 May 2026, Thomas Zimmermann <[email protected]>
> > wrote:
> > >>>> Rajat Gupta (1):
> > >>>>        drm: prevent integer overflows in dumb buffer creation
> > >>>> helpers
> > >>> Looks like this commit 5ab62dd3687b ("drm: prevent integer
> > >>> overflows in dumb buffer creation helpers") regressed in our CI,
> > >>> awaiting confirmation.
> >
> > That CI report is where?
> 
> See eg. https://intel-gfx-ci.01.org/tree/drm-tip/index.html?testfilter=kms_big
> that is https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/16308
> 
> and
> second one: https://intel-gfx-ci.01.org/tree/drm-
> tip/igt@[email protected]
> that is https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/16296
> 
> there is also comment from Chaitanya now already "issue is not seen after
> reverting and test "igt@vgem_basic@create" is passing
> 
> commit 5ab62dd3687bcc2cc542b99385aabac5c996db6f
> Author: Rajat Gupta <[email protected]>
> Date: Wed May 20 22:11:21 2026 -0700
> 
> drm: prevent integer overflows in dumb buffer creation helpers"
This proves revert is working 
(https://patchwork.freedesktop.org/series/167686/#rev1) : 
https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_167686v1/index.html?testfilter=vgem%7Cbig_fb

> 
> Br
> Jani
> 
> > >> The IGT test kms_big_fb uses max width and height from
> > >> GetResources, and
> > >> i915 and xe use max_width 16384 and max_height 16384 in mode config.
> > >>
> > >> The regressing commit adds random hard limits not based on anything:
> > >>
> > >> +       /* Reject unreasonable inputs early.  Dumb buffers are for 
> > >> software
> > >> +        * rendering; nothing legitimate needs more than 8192x8192
> > >> + at
> > 32bpp.
> > >> +        * This prevents overflows in downstream alignment helpers.
> > >> +        */
> > >> +       if (args->width >= 8192 || args->height >= 8192 || args->bpp > 
> > >> 32)
> > >> +               return -EINVAL;
> > >>
> > >> This is now in v7.1-rc6. Please revert ASAP.
> > > Ah, missed this clue in the pull request:
> > >
> > > On Fri, 29 May 2026, Thomas Zimmermann <[email protected]>
> > wrote:
> > >> here is this week's PR from drm-misc-fixes. There's one
> > >> cross-subsys commit to the dma-buf code. Commit 5ab62dd3687b ("drm:
> > >> prevent integer overflows in dumb buffer creation helpers") has not
> > >> Link tag because it went through the security list.
> > > We have the whole review and CI processes in place to catch silly
> > > mistakes, and then we proceed to shoot ourselves in the foot and
> > > bypass all of that because "security", and expedite the regressions
> > > everywhere. I'll bet this will be in stable kernels in no time too.
> > > This is stupid.
> >
> > Indeed. But that's how this fix got in.
> >
> > It fixes a possible overflow elsewhere and using dumb buffers with
> > higher values that given here is questionable. Instead of outright
> > reverting this, let's first look what actually broke.
> >
> > Best regards
> > Thomas
> >
> > >
> > > Please also read [1] with its recent updates.
> > >
> > >
> > > BR,
> > > Jani.
> > >
> > >
> > > [1]
> > > https://docs.kernel.org/process/security-bugs.html#what-qualifies-as
> > > -a
> > > -security-bug
> > >
> > >
> > >>
> > >> BR,
> > >> Jani.
> > >>
> > >>
> > >>> No matter what, it's immediately suspect because AFAICT it was not
> > >>> posted on the lists, and the commit doesn't have a Link: trailer
> > >>> pointing at the patch.
> > >>>
> > >>> This is not how we're supposed to roll. What's going on?
> > >>>
> > >>>
> > >>> BR,
> > >>> Jani.
> >
> > --
> > --
> > Thomas Zimmermann
> > Graphics Driver Developer
> > SUSE Software Solutions Germany GmbH
> > Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
> > GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG
> > Nürnberg)
> >

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