Re: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation

[Markus Armbruster]

Jeff Cody <address@hidden> writes:

> On Wed, Sep 17, 2014 at 08:33:10AM +0200, Markus Armbruster wrote:
>> Jeff Cody <address@hidden> writes:
>> 
>> > In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
>> > the various metadata table entries.  However, we write out 64kB from
>> > that buffer into the new file.  Only write out the correct 40 bytes.
>> >
>> > Signed-off-by: Jeff Cody <address@hidden>
>> > ---
>> >  block/vhdx.c | 16 ++++++++--------
>> >  1 file changed, 8 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/block/vhdx.c b/block/vhdx.c
>> > index 796b7bd..b52ec32 100644
>> > --- a/block/vhdx.c
>> > +++ b/block/vhdx.c
>> > @@ -1407,6 +1407,12 @@ exit:
>> >      return ret;
>> >  }
>> >  
>> > +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \
>> > +                                    (sizeof(VHDXFileParameters)           
>> >     +\
>> > +                                     sizeof(VHDXVirtualDiskSize)          
>> >     +\
>> > +                                     sizeof(VHDXPage83Data)               
>> >     +\
>> > +                                     
>> > sizeof(VHDXVirtualDiskLogicalSectorSize) +\
>> > +                                     
>> > sizeof(VHDXVirtualDiskPhysicalSectorSize))
>> 
>> Long lines, caused by excessive indentation.  Emacs suggests
>> 
>> #define VHDX_METADATA_ENTRY_BUFFER_SIZE         \
>>     (sizeof(VHDXFileParameters)               + \
>>      sizeof(VHDXVirtualDiskSize)              + \
>>      sizeof(VHDXPage83Data)                   + \
>>      sizeof(VHDXVirtualDiskLogicalSectorSize) + \
>>      sizeof(VHDXVirtualDiskPhysicalSectorSize))
>> 
>
> So, I was getting ready to respin this, but double checked the patch -
> it shows the lines ending on column 80 (as intended), and
> checkpatch.pl had no issue with it.  Did you accidentally (or
> intentionally!) count the leading '+' of the patch itself?

I didn't count anything, I trusted my eyes, which screamed "ugly!" :)