[PATCH v2] libsepol: fix checkpolicy dontaudit compiler bug

[Stephen Smalley <sds@tycho.nsa.gov>]

The combining logic for dontaudit rules was wrong, causing
a dontaudit A B:C *; rule to be clobbered by a dontaudit A B:C p;
rule.

Reported-by: Nick Kralevich <nnk@google.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
---
 libsepol/src/expand.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/libsepol/src/expand.c b/libsepol/src/expand.c
index 004a029..d7adbf8 100644
--- a/libsepol/src/expand.c
+++ b/libsepol/src/expand.c
@@ -1604,7 +1604,8 @@ static int expand_range_trans(expand_state_t * state,
 static avtab_ptr_t find_avtab_node(sepol_handle_t * handle,
 				   avtab_t * avtab, avtab_key_t * key,
 				   cond_av_list_t ** cond,
-				   av_extended_perms_t *xperms)
+				   av_extended_perms_t *xperms,
+				   char *alloced)
 {
 	avtab_ptr_t node;
 	avtab_datum_t avdatum;
@@ -1658,6 +1659,11 @@ static avtab_ptr_t find_avtab_node(sepol_handle_t * handle,
 			nl->next = *cond;
 			*cond = nl;
 		}
+		if (alloced)
+			*alloced = 1;
+	} else {
+		if (alloced)
+			*alloced = 0;
 	}
 
 	return node;
@@ -1750,7 +1756,7 @@ static int expand_terule_helper(sepol_handle_t * handle,
 			return EXPAND_RULE_CONFLICT;
 		}
 
-		node = find_avtab_node(handle, avtab, &avkey, cond, NULL);
+		node = find_avtab_node(handle, avtab, &avkey, cond, NULL, NULL);
 		if (!node)
 			return -1;
 		if (enabled) {
@@ -1790,6 +1796,7 @@ static int expand_avrule_helper(sepol_handle_t * handle,
 	class_perm_node_t *cur;
 	uint32_t spec = 0;
 	unsigned int i;
+	char alloced;
 
 	if (specified & AVRULE_ALLOWED) {
 		spec = AVTAB_ALLOWED;
@@ -1824,7 +1831,8 @@ static int expand_avrule_helper(sepol_handle_t * handle,
 		avkey.target_class = cur->tclass;
 		avkey.specified = spec;
 
-		node = find_avtab_node(handle, avtab, &avkey, cond, extended_perms);
+		node = find_avtab_node(handle, avtab, &avkey, cond,
+				       extended_perms, &alloced);
 		if (!node)
 			return EXPAND_RULE_ERROR;
 		if (enabled) {
@@ -1850,7 +1858,7 @@ static int expand_avrule_helper(sepol_handle_t * handle,
 			 */
 			avdatump->data &= cur->data;
 		} else if (specified & AVRULE_DONTAUDIT) {
-			if (avdatump->data)
+			if (!alloced)
 				avdatump->data &= ~cur->data;
 			else
 				avdatump->data = ~cur->data;
-- 
2.7.4