ima: add support for measuring and appraising firmware
The "security: introduce kernel_fw_from_file hook" patch defined a
new security hook to evaluate any loaded firmware that wasn't built
into the kernel.
This patch defines ima_fw_from_file(), which is called from the new
security hook, to measure and/or appraise the loaded firmware's
integrity.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index cea84d8..07099a8 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -84,6 +84,7 @@
{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, .uid = GLOBAL_ROOT_UID,
.flags = IMA_FUNC | IMA_MASK | IMA_UID},
{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
+ {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
};
static struct ima_rule_entry default_appraise_rules[] = {
@@ -241,6 +242,8 @@
return IMA_BPRM_APPRAISE;
case MODULE_CHECK:
return IMA_MODULE_APPRAISE;
+ case FIRMWARE_CHECK:
+ return IMA_FIRMWARE_APPRAISE;
case FILE_CHECK:
default:
return IMA_FILE_APPRAISE;
@@ -486,6 +489,8 @@
entry->func = FILE_CHECK;
else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
entry->func = MODULE_CHECK;
+ else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0)
+ entry->func = FIRMWARE_CHECK;
else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
|| (strcmp(args[0].from, "MMAP_CHECK") == 0))
entry->func = MMAP_CHECK;
@@ -636,6 +641,8 @@
result = -EINVAL;
else if (entry->func == MODULE_CHECK)
ima_appraise |= IMA_APPRAISE_MODULES;
+ else if (entry->func == FIRMWARE_CHECK)
+ ima_appraise |= IMA_APPRAISE_FIRMWARE;
audit_log_format(ab, "res=%d", !result);
audit_log_end(ab);
return result;