Commit a802ed0d authored by Mimi Zohar's avatar Mimi Zohar
Browse files

selftests/ima: kexec_load syscall test 



The kernel CONFIG_KEXEC_VERIFY_SIG option is limited to verifying a
kernel image's signature, when loaded via the kexec_file_load syscall.
There is no method for verifying a kernel image's signature loaded
via the kexec_load syscall.

This test verifies loading the kernel image via the kexec_load syscall
fails when the kernel CONFIG_KEXEC_VERIFY_SIG option is enabled on
systems with secureboot enabled[1].

[1] Detecting secureboot enabled is architecture specific.

Signed-off-by: default avatarMimi Zohar <zohar@linux.ibm.com>
parent 060190fb

tools/testing/selftests/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ TARGETS += firmware 
TARGETS += ftrace

TARGETS += futex

TARGETS += gpio

TARGETS += ima

TARGETS += intel_pstate

TARGETS += ipc

TARGETS += kcmp

tools/testing/selftests/ima/Makefile

0 → 100644
+11 −0
Original line number Diff line number Diff line 
# Makefile for kexec_load



uname_M := $(shell uname -m 2>/dev/null || echo not)

ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)



ifeq ($(ARCH),x86)

TEST_PROGS := test_kexec_load.sh



include ../lib.mk



endif

tools/testing/selftests/ima/config

0 → 100644
+4 −0
Original line number Diff line number Diff line 
CONFIG_IMA_APPRAISE

CONFIG_IMA_ARCH_POLICY

CONFIG_SECURITYFS

CONFIG_KEXEC_VERIFY_SIG

tools/testing/selftests/ima/test_kexec_load.sh

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+54 −0
Original line number Diff line number Diff line 
#!/bin/sh

# SPDX-License-Identifier: GPL-2.0+

# Loading a kernel image via the kexec_load syscall should fail

# when the kerne is CONFIG_KEXEC_VERIFY_SIG enabled and the system

# is booted in secureboot mode.



TEST="$0"

EFIVARFS="/sys/firmware/efi/efivars"

rc=0



# Kselftest framework requirement - SKIP code is 4.

ksft_skip=4



# kexec requires root privileges

if [ $UID != 0 ]; then

	echo "$TEST: must be run as root" >&2

	exit $ksft_skip

fi



# Make sure that efivars is mounted in the normal location

if ! grep -q "^\S\+ $EFIVARFS efivarfs" /proc/mounts; then

	echo "$TEST: efivars is not mounted on $EFIVARFS" >&2

	exit $ksft_skip

fi



# Get secureboot mode

file="$EFIVARFS/SecureBoot-*"

if [ ! -e $file ]; then

	echo "$TEST: unknown secureboot mode" >&2

	exit $ksft_skip

fi

secureboot=`hexdump $file | awk '{print substr($4,length($4),1)}'`



# kexec_load should fail in secure boot mode

KERNEL_IMAGE="/boot/vmlinuz-`uname -r`"

kexec -l $KERNEL_IMAGE &>> /dev/null

if [ $? == 0 ]; then

	kexec -u

	if [ "$secureboot" == "1" ]; then

		echo "$TEST: kexec_load succeeded [FAIL]"

		rc=1

	else

		echo "$TEST: kexec_load succeeded [PASS]"

	fi

else

	if [ "$secureboot" == "1" ]; then

		echo "$TEST: kexec_load failed [PASS]"

	else

		echo "$TEST: kexec_load failed [FAIL]"

		rc=1

	fi

fi



exit $rc

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