Add support for measuring and appraising the IMA policy itself.
Signed-off-by: Mimi Zohar <zo...@linux.vnet.ibm.com>
---
security/integrity/ima/ima.h | 2 ++
security/integrity/ima/ima_fs.c | 9 ++++++++-
security/integrity/ima/ima_main.c | 3 +++
security/integrity/ima/ima_policy.c | 10 +++++++++-
4 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 832e62a..6685968 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -149,6 +149,7 @@ enum ima_hooks {
FIRMWARE_CHECK,
KEXEC_CHECK,
INITRAMFS_CHECK,
+ POLICY_CHECK,
MAX_CHECK
};
@@ -191,6 +192,7 @@ int ima_policy_show(struct seq_file *m, void *v);
#define IMA_APPRAISE_LOG 0x04
#define IMA_APPRAISE_MODULES 0x08
#define IMA_APPRAISE_FIRMWARE 0x10
+#define IMA_APPRAISE_POLICY 0x20
#ifdef CONFIG_IMA_APPRAISE
int ima_appraise_measurement(enum ima_hooks func,
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 00ccd67..7b15e80 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -325,7 +325,14 @@ static ssize_t ima_write_policy(struct file *file, const
char __user *buf,
if (data[0] == '/')
result = ima_read_policy(data);
- else
+ else if (ima_appraise & IMA_APPRAISE_POLICY) {
+ pr_err("IMA: signed policy required\n");
+ integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
+ "policy_update", "signed policy required",
+ 1, 0);
+ if (ima_appraise & IMA_APPRAISE_ENFORCE)
+ result = -EACCES;
+ } else
result = ima_parse_add_rule(data);
mutex_unlock(&ima_write_mutex);
out_free:
diff --git a/security/integrity/ima/ima_main.c
b/security/integrity/ima/ima_main.c
index ccf9526..497a6f2 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -386,6 +386,9 @@ int ima_post_read_file(struct file *file, void *buf, loff_t
size,
case READING_KEXEC_INITRAMFS:
func = INITRAMFS_CHECK;
break;
+ case READING_POLICY:
+ func = POLICY_CHECK;
+ break;
default:
func = FILE_CHECK;
break;
diff --git a/security/integrity/ima/ima_policy.c
b/security/integrity/ima/ima_policy.c
index d02560e..39a811a 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -114,6 +114,7 @@ static struct ima_rule_entry default_measurement_rules[] = {
.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
+ {.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC},
};
static struct ima_rule_entry default_appraise_rules[] = {
@@ -616,6 +617,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry
*entry)
entry->func = KEXEC_CHECK;
else if (strcmp(args[0].from, "INITRAMFS_CHECK") == 0)
entry->func = INITRAMFS_CHECK;
+ else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
+ entry->func = POLICY_CHECK;
else
result = -EINVAL;
if (!result)
@@ -774,6 +777,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry
*entry)
temp_ima_appraise |= IMA_APPRAISE_MODULES;
else if (entry->func == FIRMWARE_CHECK)
temp_ima_appraise |= IMA_APPRAISE_FIRMWARE;
+ else if (entry->func == POLICY_CHECK)
+ temp_ima_appraise |= IMA_APPRAISE_POLICY;
audit_log_format(ab, "res=%d", !result);
audit_log_end(ab);
return result;
@@ -860,7 +865,7 @@ static char *mask_tokens[] = {
enum {
func_file = 0, func_mmap, func_bprm,
func_module, func_firmware, func_post,
- func_kexec, func_initramfs
+ func_kexec, func_initramfs, func_policy
};
static char *func_tokens[] = {
@@ -940,6 +945,9 @@ static void policy_func_show(struct seq_file *m, enum
ima_hooks func)
case INITRAMFS_CHECK:
seq_printf(m, pt(Opt_func), ft(func_initramfs));
break;
+ case POLICY_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_policy));
+ break;
default:
snprintf(tbuf, sizeof(tbuf), "%d", func);
seq_printf(m, pt(Opt_func), tbuf);
--
2.1.0
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