Re: [PATCH crypto-2.6] crypto: ccp: add timeout support in the SEV command

[Brijesh Singh]

Hi Boris,


On 09/04/2018 03:11 AM, Borislav Petkov wrote:
...

> > +
> > +static int psp_probe_timeout = 5;
> > +module_param(psp_probe_timeout, int, 0644);
> > +MODULE_PARM_DESC(psp_probe_timeout, " default timeout value, in seconds, during PSP device probe");
>
> Just a question: what prevents the user from supplying non-sensical
> values here?
>
> I think we should clamp them to only allowed values because I don't want
> to be debugging some strange bugs due to that.

Nothing prevent user from supplying a bogus number. The main question
is, clamp with what number ?

IMO, if user is overriding the default timeout number then its possible
that user is dealing with a buggy firmware which does not work with
default timeout and silently clamping the value will not help them.


- Brijesh