Re: [PATCH v1] SecurityPkg: Fix assert when setting key from FAT formatted eMMC/SD/USB

[Roman Bacik <roman.bacik@broadcom.com>]

Laszlo,

Thank you very much for your comments. I will address them and post another
patch.
Regards,

Roman

On Mon, Jul 9, 2018 at 5:24 PM, Laszlo Ersek <lersek@redhat.com> wrote:

> On 07/10/18 02:02, Laszlo Ersek wrote:
> > On 07/10/18 00:11, Roman Bacik wrote:
>
> >> +    PathName = AllocateZeroPool (PathLength);
> >> +    CopyMem (PathName, ((FILEPATH_DEVICE_PATH*)*FilePath)->PathName,
> >> PathLength);
> >
> > (3) I think it's not necessary to zero-fill the buffer, we're going to
> > overwrite it right after the allocation.
> >
> > There's a convenience function for that: AllocateCopyPool().
> >
> > (4) The number of bytes is not correct IMO. "PathLength" stands for the
> > number of bytes in the entire device path node (FILEPATH_DEVICE_PATH),
> > including Header and PathName. So, for getting the number of bytes in
> > just PathName, we should subtract the size of Header.
> >
> > Presently, we over-read the source buffer; it's not causing problems
> > because PathName is NUL-terminated.
>
> Sorry, I was unclear; I meant there were no *observable* problems. The
> over-read of the source buffer results in garbage at the end of the
> target buffer, which are later not consumed due to the terminating NUL
> appearing earlier. Still, we should not over-read the source buffer.
>
> Thanks
> Laszlo
>