ima: provide 'ima_appraise=log' kernel option

The kernel boot parameter "ima_appraise" currently defines 'off',
'enforce' and 'fix' modes.  When designing a policy and labeling
the system, access to files are either blocked in the default
'enforce' mode or automatically fixed in the 'fix' mode.  It is
beneficial to be able to run the system in a logging only mode,
without fixing it, in order to properly analyze the system. This
patch adds a 'log' mode to run the system in a permissive mode and
log the appraisal results.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

2 files changed, 5 insertions, 2 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 8e4bb883fc13..d61680dcd365 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -159,8 +159,9 @@ void ima_delete_rules(void);
 /* Appraise integrity measurements */
 #define IMA_APPRAISE_ENFORCE    0x01
 #define IMA_APPRAISE_FIX        0x02
-#define IMA_APPRAISE_MODULES    0x04
-#define IMA_APPRAISE_FIRMWARE   0x08
+#define IMA_APPRAISE_LOG        0x04
+#define IMA_APPRAISE_MODULES    0x08
+#define IMA_APPRAISE_FIRMWARE   0x10
 
 #ifdef CONFIG_IMA_APPRAISE
 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 013ec3f0e42d..2dc13fbb7e91 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -23,6 +23,8 @@ static int __init default_appraise_setup(char *str)
 {
         if (strncmp(str, "off", 3) == 0)
                 ima_appraise = 0;
+        else if (strncmp(str, "log", 3) == 0)
+                ima_appraise = IMA_APPRAISE_LOG;
         else if (strncmp(str, "fix", 3) == 0)
                 ima_appraise = IMA_APPRAISE_FIX;
         return 1;