ima: per hook cache integrity appraisal status
With the new IMA policy 'appraise_type=' option, different hooks
can require different methods for appraising a file's integrity.
For example, the existing 'ima_appraise_tcb' policy defines a
generic rule, requiring all root files to be appraised, without
specfying the appraisal method. A more specific rule could require
all kernel modules, for example, to be signed.
appraise fowner=0 func=MODULE_CHECK appraise_type=imasig
appraise fowner=0
As a result, the integrity appraisal results for the same inode, but
for different hooks, could differ. This patch caches the integrity
appraisal results on a per hook basis.
Changelog v2:
- Rename ima_cache_status() to ima_set_cache_status()
- Rename and move get_appraise_status() to ima_get_cache_status()
Changelog v0:
- include IMA_APPRAISE/APPRAISED_SUBMASK in IMA_DO/DONE_MASK (Dmitry)
- Support independent MODULE_CHECK appraise status.
- fixed IMA_XXXX_APPRAISE/APPRAISED flags
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 3cdd787..66b7f40 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -151,8 +151,10 @@
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
- /* Determine if in appraise/audit/measurement policy,
- * returns IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT bitmask. */
+ /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
+ * bitmask based on the appraise/audit/measurement policy.
+ * Included is the appraise submask.
+ */
action = ima_get_action(inode, mask, function);
if (!action)
return 0;
@@ -166,16 +168,17 @@
goto out;
/* Determine if already appraised/measured based on bitmask
- * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED,
- * IMA_AUDIT, IMA_AUDITED) */
+ * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
+ * IMA_AUDIT, IMA_AUDITED)
+ */
iint->flags |= action;
action &= IMA_DO_MASK;
action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
/* Nothing to do, just return existing appraised status */
if (!action) {
- if (iint->flags & IMA_APPRAISED)
- rc = iint->ima_status;
+ if (must_appraise)
+ rc = ima_get_cache_status(iint, function);
goto out_digsig;
}
@@ -191,8 +194,8 @@
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname);
- if (action & IMA_APPRAISE)
- rc = ima_appraise_measurement(iint, file, pathname);
+ if (action & IMA_APPRAISE_SUBMASK)
+ rc = ima_appraise_measurement(function, iint, file, pathname);
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
kfree(pathbuf);