On Wed, 2018-03-07 at 13:55 -0500, Mimi Zohar wrote: > On Wed, 2018-03-07 at 11:51 -0700, Jason Gunthorpe wrote: > > > > On Tue, Mar 06, 2018 at 11:26:26PM -0600, Jiandi An wrote: > > > > > > TPM_CRB driver is the TPM support for ARM64. If it > > > is built as module, TPM chip is registered after IMA > > > init. tpm_pcr_read() in IMA driver would fail and > > > display the following message even though eventually > > > there is TPM chip on the system: > > > > > > ima: No TPM chip found, activating TPM-bypass! (rc=-19) > > > > > > Fix IMA Kconfig to select TPM_CRB so TPM_CRB driver is > > > built in kernel and initializes before IMA driver. > > > > > > Signed-off-by: Jiandi An <anjiandi@xxxxxxxxxxxxxx> > > > security/integrity/ima/Kconfig | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/security/integrity/ima/Kconfig > > > b/security/integrity/ima/Kconfig > > > index 35ef693..6a8f677 100644 > > > +++ b/security/integrity/ima/Kconfig > > > @@ -10,6 +10,7 @@ config IMA > > > select CRYPTO_HASH_INFO > > > select TCG_TPM if HAS_IOMEM && !UML > > > select TCG_TIS if TCG_TPM && X86 Well, this explains why IMA doesn't work on one of my X86 systems: it's got a non i2c infineon TPM. > > > + select TCG_CRB if TCG_TPM && ACPI > > > select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES > > > help > > > The Trusted Computing Group(TCG) runtime Integrity > > > > This seems really weird, why are any specific TPM drivers linked to > > IMA config, we have lots of drivers.. > > > > I don't think I've ever seen this pattern in Kconfig before? > > As you've seen by the current discussions, the TPM driver needs to be > initialized prior to IMA. Otherwise IMA goes into TPM-bypass mode. > That implies that the TPM must be builtin to the kernel, and not as > a kernel module. Actually, that's not necessarily true: If we don't begin appraisal until after the initrd phase, then the initrd can load TPM modules before IMA starts. This would involve a bit of code rejigging to not require a TPM until IMA wants to write its first measurement, but it looks doable and would get us out of having to second guess TPM selections. James
