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

[Davidlohr Bueso <davidlohr@hp.com>]

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@nvidia.com> wrote:
> >
> >  > Use ARRAY_SIZE instead of sizeof to get proper max for label
> >  > length.
> >  >
> >  > Signed-off-by: Antti P Miettinen <amiettinen@nvidia.com>
> >  > Reviewed-by: Hiroshi Doyu <hdoyu@nvidia.com>
> >  > Tested-by: Hiroshi Doyu <hdoyu@nvidia.com>
> >
> > 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@chromium.org>
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@chromium.org>
    Signed-off-by: Jens Axboe <jaxboe@fusionio.com>


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