mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-23 11:04:44 +08:00
cbc0425d3d
In addition to the PE/COFF and IMA xattr signatures, the kexec kernel image can be signed with an appended signature, using the same scripts/sign-file tool that is used to sign kernel modules. This patch adds support for detecting a kernel image signed with an appended signature and updates the existing test messages appropriately. Reviewed-by: Petr Vorel <pvorel@suse.cz> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Jordan Hand <jorhand@linux.microsoft.com> (x86_64 QEMU) Tested-by: Jordan Hand <jorhand@linux.microsoft.com> (x86_64 QEMU) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
239 lines
6.6 KiB
Bash
Executable File
239 lines
6.6 KiB
Bash
Executable File
#!/bin/sh
|
|
# SPDX-License-Identifier: GPL-2.0
|
|
#
|
|
# Loading a kernel image via the kexec_file_load syscall can verify either
|
|
# the IMA signature stored in the security.ima xattr or the PE signature,
|
|
# both signatures depending on the IMA policy, or none.
|
|
#
|
|
# To determine whether the kernel image is signed, this test depends
|
|
# on pesign and getfattr. This test also requires the kernel to be
|
|
# built with CONFIG_IKCONFIG enabled and either CONFIG_IKCONFIG_PROC
|
|
# enabled or access to the extract-ikconfig script.
|
|
|
|
TEST="KEXEC_FILE_LOAD"
|
|
. ./kexec_common_lib.sh
|
|
|
|
trap "{ rm -f $IKCONFIG ; }" EXIT
|
|
|
|
# Some of the IMA builtin policies may require the kexec kernel image to
|
|
# be signed, but these policy rules may be replaced with a custom
|
|
# policy. Only CONFIG_IMA_APPRAISE_REQUIRE_KEXEC_SIGS persists after
|
|
# loading a custom policy. Check if it is enabled, before reading the
|
|
# IMA runtime sysfs policy file.
|
|
# Return 1 for IMA signature required and 0 for not required.
|
|
is_ima_sig_required()
|
|
{
|
|
local ret=0
|
|
|
|
kconfig_enabled "CONFIG_IMA_APPRAISE_REQUIRE_KEXEC_SIGS=y" \
|
|
"IMA kernel image signature required"
|
|
if [ $? -eq 1 ]; then
|
|
log_info "IMA signature required"
|
|
return 1
|
|
fi
|
|
|
|
# The architecture specific or a custom policy may require the
|
|
# kexec kernel image be signed. Policy rules are walked
|
|
# sequentially. As a result, a policy rule may be defined, but
|
|
# might not necessarily be used. This test assumes if a policy
|
|
# rule is specified, that is the intent.
|
|
|
|
# First check for appended signature (modsig), then xattr
|
|
if [ $ima_read_policy -eq 1 ]; then
|
|
check_ima_policy "appraise" "func=KEXEC_KERNEL_CHECK" \
|
|
"appraise_type=imasig|modsig"
|
|
ret=$?
|
|
if [ $ret -eq 1 ]; then
|
|
log_info "IMA or appended(modsig) signature required"
|
|
else
|
|
check_ima_policy "appraise" "func=KEXEC_KERNEL_CHECK" \
|
|
"appraise_type=imasig"
|
|
ret=$?
|
|
[ $ret -eq 1 ] && log_info "IMA signature required";
|
|
fi
|
|
fi
|
|
return $ret
|
|
}
|
|
|
|
# The kexec_file_load_test() is complicated enough, require pesign.
|
|
# Return 1 for PE signature found and 0 for not found.
|
|
check_for_pesig()
|
|
{
|
|
which pesign > /dev/null 2>&1 || log_skip "pesign not found"
|
|
|
|
pesign -i $KERNEL_IMAGE --show-signature | grep -q "No signatures"
|
|
local ret=$?
|
|
if [ $ret -eq 1 ]; then
|
|
log_info "kexec kernel image PE signed"
|
|
else
|
|
log_info "kexec kernel image not PE signed"
|
|
fi
|
|
return $ret
|
|
}
|
|
|
|
# The kexec_file_load_test() is complicated enough, require getfattr.
|
|
# Return 1 for IMA signature found and 0 for not found.
|
|
check_for_imasig()
|
|
{
|
|
local ret=0
|
|
|
|
which getfattr > /dev/null 2>&1
|
|
if [ $? -eq 1 ]; then
|
|
log_skip "getfattr not found"
|
|
fi
|
|
|
|
line=$(getfattr -n security.ima -e hex --absolute-names $KERNEL_IMAGE 2>&1)
|
|
echo $line | grep -q "security.ima=0x03"
|
|
if [ $? -eq 0 ]; then
|
|
ret=1
|
|
log_info "kexec kernel image IMA signed"
|
|
else
|
|
log_info "kexec kernel image not IMA signed"
|
|
fi
|
|
return $ret
|
|
}
|
|
|
|
# Return 1 for appended signature (modsig) found and 0 for not found.
|
|
check_for_modsig()
|
|
{
|
|
local module_sig_string="~Module signature appended~"
|
|
local sig="$(tail --bytes $((${#module_sig_string} + 1)) $KERNEL_IMAGE)"
|
|
local ret=0
|
|
|
|
if [ "$sig" == "$module_sig_string" ]; then
|
|
ret=1
|
|
log_info "kexec kernel image modsig signed"
|
|
else
|
|
log_info "kexec kernel image not modsig signed"
|
|
fi
|
|
return $ret
|
|
}
|
|
|
|
kexec_file_load_test()
|
|
{
|
|
local succeed_msg="kexec_file_load succeeded"
|
|
local failed_msg="kexec_file_load failed"
|
|
local key_msg="try enabling the CONFIG_INTEGRITY_PLATFORM_KEYRING"
|
|
|
|
line=$(kexec --load --kexec-file-syscall $KERNEL_IMAGE 2>&1)
|
|
|
|
if [ $? -eq 0 ]; then
|
|
kexec --unload --kexec-file-syscall
|
|
|
|
# In secureboot mode with an architecture specific
|
|
# policy, make sure either an IMA or PE signature exists.
|
|
if [ $secureboot -eq 1 ] && [ $arch_policy -eq 1 ] && \
|
|
[ $ima_signed -eq 0 ] && [ $pe_signed -eq 0 ] \
|
|
&& [ $ima_modsig -eq 0 ]; then
|
|
log_fail "$succeed_msg (missing sig)"
|
|
fi
|
|
|
|
if [ $kexec_sig_required -eq 1 -o $pe_sig_required -eq 1 ] \
|
|
&& [ $pe_signed -eq 0 ]; then
|
|
log_fail "$succeed_msg (missing PE sig)"
|
|
fi
|
|
|
|
if [ $ima_sig_required -eq 1 ] && [ $ima_signed -eq 0 ] \
|
|
&& [ $ima_modsig -eq 0 ]; then
|
|
log_fail "$succeed_msg (missing IMA sig)"
|
|
fi
|
|
|
|
if [ $pe_sig_required -eq 0 ] && [ $ima_appraise -eq 1 ] \
|
|
&& [ $ima_sig_required -eq 0 ] && [ $ima_signed -eq 0 ] \
|
|
&& [ $ima_read_policy -eq 0 ]; then
|
|
log_fail "$succeed_msg (possibly missing IMA sig)"
|
|
fi
|
|
|
|
if [ $pe_sig_required -eq 0 ] && [ $ima_appraise -eq 0 ]; then
|
|
log_info "No signature verification required"
|
|
elif [ $pe_sig_required -eq 0 ] && [ $ima_appraise -eq 1 ] \
|
|
&& [ $ima_sig_required -eq 0 ] && [ $ima_signed -eq 0 ] \
|
|
&& [ $ima_read_policy -eq 1 ]; then
|
|
log_info "No signature verification required"
|
|
fi
|
|
|
|
log_pass "$succeed_msg"
|
|
fi
|
|
|
|
# Check the reason for the kexec_file_load failure
|
|
echo $line | grep -q "Required key not available"
|
|
if [ $? -eq 0 ]; then
|
|
if [ $platform_keyring -eq 0 ]; then
|
|
log_pass "$failed_msg (-ENOKEY), $key_msg"
|
|
else
|
|
log_pass "$failed_msg (-ENOKEY)"
|
|
fi
|
|
fi
|
|
|
|
if [ $kexec_sig_required -eq 1 -o $pe_sig_required -eq 1 ] \
|
|
&& [ $pe_signed -eq 0 ]; then
|
|
log_pass "$failed_msg (missing PE sig)"
|
|
fi
|
|
|
|
if [ $ima_sig_required -eq 1 ] && [ $ima_signed -eq 0 ]; then
|
|
log_pass "$failed_msg (missing IMA sig)"
|
|
fi
|
|
|
|
if [ $pe_sig_required -eq 0 ] && [ $ima_appraise -eq 1 ] \
|
|
&& [ $ima_sig_required -eq 0 ] && [ $ima_read_policy -eq 0 ] \
|
|
&& [ $ima_signed -eq 0 ]; then
|
|
log_pass "$failed_msg (possibly missing IMA sig)"
|
|
fi
|
|
|
|
log_pass "$failed_msg"
|
|
return 0
|
|
}
|
|
|
|
# kexec requires root privileges
|
|
require_root_privileges
|
|
|
|
# get the kernel config
|
|
get_kconfig
|
|
|
|
kconfig_enabled "CONFIG_KEXEC_FILE=y" "kexec_file_load is enabled"
|
|
if [ $? -eq 0 ]; then
|
|
log_skip "kexec_file_load is not enabled"
|
|
fi
|
|
|
|
# Determine which kernel config options are enabled
|
|
kconfig_enabled "CONFIG_IMA_APPRAISE=y" "IMA enabled"
|
|
ima_appraise=$?
|
|
|
|
kconfig_enabled "CONFIG_IMA_ARCH_POLICY=y" \
|
|
"architecture specific policy enabled"
|
|
arch_policy=$?
|
|
|
|
kconfig_enabled "CONFIG_INTEGRITY_PLATFORM_KEYRING=y" \
|
|
"platform keyring enabled"
|
|
platform_keyring=$?
|
|
|
|
kconfig_enabled "CONFIG_IMA_READ_POLICY=y" "reading IMA policy permitted"
|
|
ima_read_policy=$?
|
|
|
|
kconfig_enabled "CONFIG_KEXEC_SIG_FORCE=y" \
|
|
"kexec signed kernel image required"
|
|
kexec_sig_required=$?
|
|
|
|
kconfig_enabled "CONFIG_KEXEC_BZIMAGE_VERIFY_SIG=y" \
|
|
"PE signed kernel image required"
|
|
pe_sig_required=$?
|
|
|
|
is_ima_sig_required
|
|
ima_sig_required=$?
|
|
|
|
get_secureboot_mode
|
|
secureboot=$?
|
|
|
|
# Are there pe and ima signatures
|
|
check_for_pesig
|
|
pe_signed=$?
|
|
|
|
check_for_imasig
|
|
ima_signed=$?
|
|
|
|
check_for_modsig
|
|
ima_modsig=$?
|
|
|
|
# Test loading the kernel image via kexec_file_load syscall
|
|
kexec_file_load_test
|