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

[Bruno Meneguele]

On Tue, Jul 21, 2020 at 01:26:16PM -0400, Mimi Zohar wrote:
> 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.  This prevents properly labeling the
> > > > > filesystem on systems where secure boot is supported, but not enabled on the
> > > > > platform.  Only 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?  Is the colon being
> > > used as a delimiter when parsing the kernel logs?  Should the second
> > > colon be replaced with a hyphen?  (No need to repost.  I'll fix it
> > > up.)
> > >  
> > 
> > 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.  FYI, it's now in next-integrity.
> 
> Mimi
> 

Thanks Mimi.

-- 
bmeneg 
PGP Key: http://bmeneg.com/pubkey.txt
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