Re: [PATCH 5/8] pstore: Fix long-term implicit conversions in the compression routines

From: Kees Cook
Date: Thu Oct 06 2022 - 19:37:03 EST

On Thu, Oct 06, 2022 at 07:42:09PM -0300, Guilherme G. Piccoli wrote:
> The pstore infrastructure is capable of compressing collected logs,
> relying for that in many compression "libraries" present on kernel.
> Happens that the (de)compression code in pstore performs many
> implicit conversions from unsigned int/size_t to int, and vice-versa.
> Specially in the compress buffer size calculation, we notice that
> even the libs are not consistent, some of them return int, most of
> them unsigned int and others rely on preprocessor calculation.
> Here is an attempt to make it consistent: since we're talking
> about buffer sizes, let's go with unsigned types, since negative
> sizes don't make sense.

Thanks for this! I want to go through this more carefully, but I'm a fan
of the clean-up. I'd also like to get Ard's compression refactor landed
again, and then do this on top of it.

Kees Cook