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* UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.h:1101:17
@ 2026-02-23 23:16 Janusz Krzysztofik
  2026-02-28  0:34 ` Jason Gunthorpe
  0 siblings, 1 reply; 3+ messages in thread
From: Janusz Krzysztofik @ 2026-02-23 23:16 UTC (permalink / raw)
  To: iommu; +Cc: Joerg Roedel, Will Deacon, Robin Murphy, David Woodhouse,
	Lu Baolu

Hello,

Please have a look at 
https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15478

For me it looks like an IOMMU issue.  I've added there a comment that 
summarizes my findings.

Thanks,
Janusz



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.h:1101:17
  2026-02-23 23:16 UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.h:1101:17 Janusz Krzysztofik
@ 2026-02-28  0:34 ` Jason Gunthorpe
  2026-03-09 10:57   ` Janusz Krzysztofik
  0 siblings, 1 reply; 3+ messages in thread
From: Jason Gunthorpe @ 2026-02-28  0:34 UTC (permalink / raw)
  To: Janusz Krzysztofik
  Cc: iommu, Joerg Roedel, Will Deacon, Robin Murphy, David Woodhouse,
	Lu Baolu

On Tue, Feb 24, 2026 at 12:16:32AM +0100, Janusz Krzysztofik wrote:
> Hello,
> 
> Please have a look at 
> https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15478
> 
> For me it looks like an IOMMU issue.  I've added there a comment that 
> summarizes my findings.

If I recall there are some error flows that will push a 0 length
gather to the driver, it is supposed to ignore a gather where
start == end

Do you think that is the issue?

Jason

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.h:1101:17
  2026-02-28  0:34 ` Jason Gunthorpe
@ 2026-03-09 10:57   ` Janusz Krzysztofik
  0 siblings, 0 replies; 3+ messages in thread
From: Janusz Krzysztofik @ 2026-03-09 10:57 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: iommu, Joerg Roedel, Will Deacon, Robin Murphy, David Woodhouse,
	Lu Baolu

On Saturday, 28 February 2026 01:34:05 CET Jason Gunthorpe wrote:
> On Tue, Feb 24, 2026 at 12:16:32AM +0100, Janusz Krzysztofik wrote:
> > Hello,
> > 
> > Please have a look at 
> > https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15478
> > 
> > For me it looks like an IOMMU issue.  I've added there a comment that 
> > summarizes my findings.
> 
> If I recall there are some error flows that will push a 0 length
> gather to the driver, it is supposed to ignore a gather where
> start == end
> 
> Do you think that is the issue?

AFAICT I was observing unsuccessful mappings related to OOM conditions, 
followed by 0 sized unmap requests that were triggering the issue.

Thanks,
Janusz

> 
> Jason
> 





^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2026-03-09 11:28 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-02-23 23:16 UBSAN: shift-out-of-bounds in drivers/iommu/intel/iommu.h:1101:17 Janusz Krzysztofik
2026-02-28  0:34 ` Jason Gunthorpe
2026-03-09 10:57   ` Janusz Krzysztofik

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