Re: [PATCH v2] grub-core/disk/cryptodisk.c: Fix unintentional integer overflow

[Daniel Kiper]

On Sat, Oct 15, 2022 at 11:13:09AM +0200, Patrick Steinhardt wrote:
> On Fri, Oct 14, 2022 at 05:47:08PM -0400, Alec Brown wrote:
> > In the function grub_cryptodisk_endecrypt(), a for loop is incrementing the
> > variable i by (1U << log_sector_size). The variable i is of type grub_size_t
> > which is a 64-bit unsigned integer on x86_64 architecture. On the other 
> > hand, 1U
> > is a 32-bit unsigned integer. By performing a left shift on a 32-bit value 
> > and
> > assigning it to a 64-bit variable, the 64-bit variable may have incorrect 
> > values
> > in the high 32-bits if the shift has an overflow. To avoid this, we replace 
> > 1U
> > with (grub_size_t) 1.
> >
> > Fixes: CID 307788
> >
> > Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
>
> Reviewed-by: Patrick Steinhardt <ps@pks.im>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

Daniel