4 files changed, 27 insertions, 19 deletions

diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
index 30f119b..820313a 100644
--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c
@@ -213,7 +213,12 @@ netlbl_import_failure:
 }
 #endif /* CONFIG_NETLABEL */
 
-int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
+/*
+ * Check to see if all the bits set in e2 are also set in e1. Optionally,
+ * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
+ * last_e2bit.
+ */
+int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
 {
 	struct ebitmap_node *n1, *n2;
 	int i;
@@ -223,14 +228,25 @@ int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
 
 	n1 = e1->node;
 	n2 = e2->node;
+
 	while (n1 && n2 && (n1->startbit <= n2->startbit)) {
 		if (n1->startbit < n2->startbit) {
 			n1 = n1->next;
 			continue;
 		}
-		for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
+		for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
+			i--;	/* Skip trailing NULL map entries */
+		if (last_e2bit && (i >= 0)) {
+			u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
+					 __fls(n2->maps[i]);
+			if (lastsetbit > last_e2bit)
+				return 0;
+		}
+
+		while (i >= 0) {
 			if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
 				return 0;
+			i--;
 		}
 
 		n1 = n1->next;
diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h
index 922f8af..e7eb3a9 100644
--- a/security/selinux/ss/ebitmap.h
+++ b/security/selinux/ss/ebitmap.h
@@ -117,7 +117,7 @@ static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
 
 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
-int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
+int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
 void ebitmap_destroy(struct ebitmap *e);
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index 40de8d3..c85bc1e 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -160,8 +160,6 @@ void mls_sid_to_context(struct context *context,
 int mls_level_isvalid(struct policydb *p, struct mls_level *l)
 {
 	struct level_datum *levdatum;
-	struct ebitmap_node *node;
-	int i;
 
 	if (!l->sens || l->sens > p->p_levels.nprim)
 		return 0;
@@ -170,19 +168,13 @@ int mls_level_isvalid(struct policydb *p, struct mls_level *l)
 	if (!levdatum)
 		return 0;
 
-	ebitmap_for_each_positive_bit(&l->cat, node, i) {
-		if (i > p->p_cats.nprim)
-			return 0;
-		if (!ebitmap_get_bit(&levdatum->level->cat, i)) {
-			/*
-			 * Category may not be associated with
-			 * sensitivity.
-			 */
-			return 0;
-		}
-	}
-
-	return 1;
+	/*
+	 * Return 1 iff all the bits set in l->cat are also be set in
+	 * levdatum->level->cat and no bit in l->cat is larger than
+	 * p->p_cats.nprim.
+	 */
+	return ebitmap_contains(&levdatum->level->cat, &l->cat,
+				p->p_cats.nprim);
 }
 
 int mls_range_isvalid(struct policydb *p, struct mls_range *r)
diff --git a/security/selinux/ss/mls_types.h b/security/selinux/ss/mls_types.h
index 03bed52..e936487 100644
--- a/security/selinux/ss/mls_types.h
+++ b/security/selinux/ss/mls_types.h
@@ -35,7 +35,7 @@ static inline int mls_level_eq(struct mls_level *l1, struct mls_level *l2)
 static inline int mls_level_dom(struct mls_level *l1, struct mls_level *l2)
 {
 	return ((l1->sens >= l2->sens) &&
-		ebitmap_contains(&l1->cat, &l2->cat));
+		ebitmap_contains(&l1->cat, &l2->cat, 0));
 }
 
 #define mls_level_incomp(l1, l2) \