Re: [PATCH] fs: partitions: efi: Fix bound check

From: Davidlohr Bueso
Date: Wed Nov 20 2013 - 12:47:08 EST


On Wed, 2013-11-20 at 08:18 +0100, Antti Miettinen wrote:
> On 20.11.2013 02:04, Andrew Morton wrote:
> > On Fri, 15 Nov 2013 19:14:22 +0200 (EET) Antti P Miettinen
> > <amiettinen@xxxxxxxxxx> wrote:
> >
> > > Use ARRAY_SIZE instead of sizeof to get proper max for label
> > > length.
> > >
> > > Signed-off-by: Antti P Miettinen <amiettinen@xxxxxxxxxx>
> > > Reviewed-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
> > > Tested-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
> >
> > When fixing a bug, please provide a description of the user-visible
> > impact of that bug. This is so that others can decide which kernel
> > version(s) need the patch.
> >
> > Hiroshi Doyu tested this patch, so I assume there was some observable
> > misbehaviour to test. Please fully describe that.
>
> Since this is just a read out of bounds it's not that bad, but the
> problem becomes user-visible e.g. if one tries to use
> CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_RODATA, at least with some
> enhancements from Hiroshi. Of course the destination array can contain
> garbage when we read beyond the end of source array so that would be
> another user-visible problem.
>

Cc'ing Will - this path as been untouched since it's inclusion back in
2.6.37:

commit eec7ecfede74bb996060efefd5c157acd5794e8a
Author: Will Drewry <wad@xxxxxxxxxxxx>
Date: Tue Aug 31 15:47:06 2010 -0500

genhd, efi: add efi partition metadata to hd_structs

This change extends the partition_meta_info structure to
support EFI GPT-specific metadata and ensures that data
is copied in on partition scanning.

Signed-off-by: Will Drewry <wad@xxxxxxxxxxxx>
Signed-off-by: Jens Axboe <jaxboe@xxxxxxxxxxxx>


> Should I send a new version with better commit message?
>
> --Antti


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