Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

From: Lakshmi Ramasubramanian
Date: Wed Feb 10 2021 - 12:36:50 EST


On 2/10/21 9:15 AM, Rob Herring wrote:
On Tue, Feb 09, 2021 at 10:21:50AM -0800, Lakshmi Ramasubramanian wrote:
On kexec file load Integrity Measurement Architecture (IMA) subsystem
may verify the IMA signature of the kernel and initramfs, and measure
it. The command line parameters passed to the kernel in the kexec call
may also be measured by IMA. A remote attestation service can verify
a TPM quote based on the TPM event log, the IMA measurement list, and
the TPM PCR data. This can be achieved only if the IMA measurement log
is carried over from the current kernel to the next kernel across
the kexec call.

powerpc already supports carrying forward the IMA measurement log on
kexec. This patch set adds support for carrying forward the IMA
measurement log on kexec on ARM64.

This patch set moves the platform independent code defined for powerpc
such that it can be reused for other platforms as well. A chosen node
"linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
the address and the size of the memory reserved to carry
the IMA measurement log.

This patch set has been tested for ARM64 platform using QEMU.
I would like help from the community for testing this change on powerpc.
Thanks.

This patch set is based on
commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
"next-integrity" branch.

Is that a hard dependency still? Given this is now almost entirely
deleting arch code and adding drivers/of/ code, I was going to apply it.


I tried applying the patches in Linus' mainline branch -
PATCH #5 0005-powerpc-Move-ima-buffer-fields-to-struct-kimage.patch doesn't apply.

But if I apply the dependent patch set (link given below), all the patches in this patch set apply fine.

https://patchwork.kernel.org/project/linux-integrity/patch/20210204174951.25771-2-nramas@xxxxxxxxxxxxxxxxxxx/

thanks,
-lakshmi