Re: [PATCH v6] ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtime

[Mimi Zohar]

On Mon, 2020-07-20 at 12:38 -0300, Bruno Meneguele wrote:
> On Mon, Jul 20, 2020 at 10:56:55AM -0400, Mimi Zohar wrote:
> > On Mon, 2020-07-20 at 10:40 -0400, Nayna wrote:
> > > On 7/13/20 12:48 PM, Bruno Meneguele wrote:
> > > > The IMA_APPRAISE_BOOTPARAM config allows enabling different "ima_appraise="
> > > > modes - log, fix, enforce - at run time, but not when IMA architecture
> > > > specific policies are enabled. ÂThis prevents properly labeling the
> > > > filesystem on systems where secure boot is supported, but not enabled on the
> > > > platform. ÂOnly when secure boot is actually enabled should these IMA
> > > > appraise modes be disabled.
> > > >
> > > > This patch removes the compile time dependency and makes it a runtime
> > > > decision, based on the secure boot state of that platform.
> > > >
> > > > Test results as follows:
> > > >
> > > > -> x86-64 with secure boot enabled
> > > >
> > > > [    0.015637] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
> > > > [    0.015668] ima: Secure boot enabled: ignoring ima_appraise=fix boot parameter option
> > > >
> > 
> > Is it common to have two colons in the same line? ÂIs the colon being
> > used as a delimiter when parsing the kernel logs? ÂShould the second
> > colon be replaced with a hyphen? Â(No need to repost. ÂI'll fix it
> > up.)
> > Â
> 
> AFAICS it has been used without any limitations, e.g:
> 
> PM: hibernation: Registered nosave memory: [mem 0x00000000-0x00000fff]
> clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 133484873504 ns
> microcode: CPU0: patch_level=0x08701013
> Lockdown: modprobe: unsigned module loading is restricted; see man kernel_lockdown.7
> ...
> 
> I'd say we're fine using it.

Ok. ÂFYI, it's now in next-integrity.

Mimi