[PATCH v4] x86/kexec: fix potential cmem->ranges out of bounds

[Andrew Morton]

On Fri, 9 May 2025 17:58:01 +0800 Baoquan He <bhe at redhat.com> wrote:

> > The bad commit was introduced in 2021 but only recent gcc-15 supports
> > __counted_by. That's why we don't see this UBSAN warning until this
> > year. And although this UBSAN warning is scary enough, fortunately it
> > doesn't cause a real problem.
> > 
> > > 
> > > Baoquan, please re-review this?
> > > 
> > > A -stable backport is clearly required.  A Fixes: would be nice, but I
> > > assume this goes back a long time so it isn't worth spending a lot of
> > > time working out when this was introduced.
> > 
> > So I believe the correct fix should be as follows,
> 
> Thanks for testing and investigation into these. Could you arrange this
> into formal patches based on your testing and analysis? 
> 
> It would be great if you can include Fuqiang's patch since it has
> conflict with your LUKS patch. This can facilitate patch merging for
> Andrew. Thanks in advance.

Yes please, I'm a bit lost here. 
x86-kexec-fix-potential-cmem-ranges-out-of-bounds.patch is not
presently in mm.git and I'd appreciate clarity on how to resolve the
conflicts which a new version of
x86-kexec-fix-potential-cmem-ranges-out-of-bounds.patch will produce.