IMA during kexec(kexec file load) verifies the kernel signature and measures
the signature of the kernel. The signature in the logs can be used to verfiy the
authenticity of the kernel. The logs don not get carried over kexec and thus
remote attesation cannot verify the signature of the running kernel.
Add a new chosen node entry linux,ima-kexec-buffer to hold the address and
the size of the memory reserved to carry the IMA measurement log.
Tested on:
arm64 with Uboot
Changelog:
v1:
Refactoring carrying over IMA measuremnet logs over Kexec. This patch
moves the non-architecture specific code out of powerpc and adds to
security/ima.(Suggested by Thiago)
Add Documentation regarding the ima-kexec-buffer node in the chosen
node documentation
v0:
Add a layer of abstraction to use the memory reserved by device tree
for ima buffer pass.
Add support for ima buffer pass using reserved memory for arm64 kexec.
Update the arch sepcific code path in kexec file load to store the
ima buffer in the reserved memory. The same reserved memory is read
on kexec or cold boot.
Documentation/devicetree/bindings/chosen.txt | 17 +++
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/ima.h | 24 +++
arch/arm64/include/asm/kexec.h | 3 +
arch/arm64/kernel/machine_kexec_file.c | 47 +++++-
arch/powerpc/include/asm/ima.h | 9 --
arch/powerpc/kexec/ima.c | 117 +-------------
security/integrity/ima/ima_kexec.c | 151 +++++++++++++++++++
8 files changed, 236 insertions(+), 133 deletions(-)
create mode 100644 arch/arm64/include/asm/ima.h
--
2.25.1
