ima: differentiate appraise status only for hook specific rules
Different hooks can require different methods for appraising a
file's integrity. As a result, an integrity appraisal status is
cached on a per hook basis.
Only a hook specific rule, requires the inode to be re-appraised.
This patch eliminates unnecessary appraisals.
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 66b7f40..3e751a9 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -146,7 +146,7 @@
struct integrity_iint_cache *iint;
char *pathbuf = NULL;
const char *pathname = NULL;
- int rc = -ENOMEM, action, must_appraise;
+ int rc = -ENOMEM, action, must_appraise, _func;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
@@ -161,6 +161,9 @@
must_appraise = action & IMA_APPRAISE;
+ /* Is the appraise rule hook specific? */
+ _func = (action & IMA_FILE_APPRAISE) ? FILE_CHECK : function;
+
mutex_lock(&inode->i_mutex);
iint = integrity_inode_get(inode);
@@ -178,7 +181,7 @@
/* Nothing to do, just return existing appraised status */
if (!action) {
if (must_appraise)
- rc = ima_get_cache_status(iint, function);
+ rc = ima_get_cache_status(iint, _func);
goto out_digsig;
}
@@ -195,7 +198,7 @@
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname);
if (action & IMA_APPRAISE_SUBMASK)
- rc = ima_appraise_measurement(function, iint, file, pathname);
+ rc = ima_appraise_measurement(_func, iint, file, pathname);
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
kfree(pathbuf);
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 4d7c0ae..4adcd0f 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -220,10 +220,13 @@
/*
* In addition to knowing that we need to appraise the file in general,
- * we need to differentiate between calling hooks.
+ * we need to differentiate between calling hooks, for hook specific rules.
*/
-static int get_subaction(int func)
+static int get_subaction(struct ima_rule_entry *rule, int func)
{
+ if (!(rule->flags & IMA_FUNC))
+ return IMA_FILE_APPRAISE;
+
switch(func) {
case MMAP_CHECK:
return IMA_MMAP_APPRAISE;
@@ -268,7 +271,7 @@
action |= entry->action & IMA_DO_MASK;
if (entry->action & IMA_APPRAISE)
- action |= get_subaction(func);
+ action |= get_subaction(entry, func);
if (entry->action & IMA_DO_MASK)
actmask &= ~(entry->action | entry->action << 1);