Re: [PATCH 2/2] keys, trusted: seal with a policy

From: Jarkko Sakkinen
Date: Tue Dec 08 2015 - 15:24:37 EST


On Tue, Dec 08, 2015 at 01:01:02PM +0200, Jarkko Sakkinen wrote:
> On Tue, Dec 08, 2015 at 09:35:05AM +1100, James Morris wrote:
> > On Mon, 7 Dec 2015, Jarkko Sakkinen wrote:
> >
> > > On Fri, Nov 20, 2015 at 01:34:35PM +1100, James Morris wrote:
> > > > On Wed, 18 Nov 2015, Jarkko Sakkinen wrote:
> > > >
> > > > > On Wed, Nov 18, 2015 at 11:21:01AM +1100, James Morris wrote:
> > > > > > On Tue, 17 Nov 2015, Jarkko Sakkinen wrote:
> > > > > >
> > > > > > > }
> > > > > > > break;
> > > > > > > + case Opt_policydigest:
> > > > > > > + if (!tpm2 ||
> > > > > > > + strlen(args[0].from) != (2 * opt->digest_len))
> > > > > > > + return -EINVAL;
> > > > > > > + kfree(opt->policydigest);
> > > > > > > + opt->policydigest = kzalloc(opt->digest_len,
> > > > > > > + GFP_KERNEL);
> > > > > >
> > > > > > Is it correct to kfree opt->policydigest here before allocating it?
> > > > >
> > > > > I think so. The same option might be encountered multiple times.
> > > >
> > > > This would surely signify an error?
> > >
> > > I'm following the semantics of other options. That's why I implemented
> > > it that way for example:
> > >
> > > keyctl add trusted kmk "new 32 keyhandle=0x80000000 keyhandle=0x80000000"
> > >
> > > is perfectly OK. I just thought that it'd be more odd if this option
> > > behaved in a different way...
> >
> > It seems broken to me -- if you're messing up keyctl commands you might
> > want to know about it, but we should remain consistent.
>
> So should I return error if policyhandle/digest appears a second time? I
> agree that it'd be better to return -EINVAL.
>
> The existing behavior is such that any option can appear multiple times
> and I chose to be consistent with that.

Mimi, David?

/Jarkko
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