Re: [PATCH 2/2] reboot: fix parsing of reboot cpu number

[Kees Cook]

On Fri, Oct 16, 2020 at 08:09:07PM +0200, Matteo Croce wrote:
> From: Matteo Croce <mcroce@xxxxxxxxxxxxx>
> 
> The kernel cmdline reboot= argument allows to specify the CPU used
> for rebooting, with the syntax `s####` among the other flags, e.g.
> 
>   reboot=soft,s4
>   reboot=warm,s31,force
> 
> In the early days the parsing was done with simple_strtoul(), later
> deprecated in favor of the safer kstrtoint() which handles overflow.
> 
> But kstrtoint() returns -EINVAL if there are non-digit characters
> in a string, so if this flag is not the last given, it's silently
> ignored as well as the subsequent ones.
> 
> To fix it, revert the usage of simple_strtoul(), which is no longer
> deprecated, and restore the old behaviour.

It is? Is there a reference, because this was never updated:
https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull

-- 
Kees Cook