selinux: convert part of the sym_val_to_name array to use flex_array

The sym_val_to_name type array can be quite large as it grows linearly with
the number of types.  With known policies having over 5k types these
allocations are growing large enough that they are likely to fail.  Convert
those to flex_array so no allocation is larger than PAGE_SIZE

Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 82 insertions, 27 deletions

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index af41fdfe1a71..5adca670e5af 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -254,12 +254,17 @@ static int common_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct common_datum *comdatum;
+	struct flex_array *fa;
 
 	comdatum = datum;
 	p = datap;
 	if (!comdatum->value || comdatum->value > p->p_commons.nprim)
 		return -EINVAL;
-	p->p_common_val_to_name[comdatum->value - 1] = key;
+
+	fa = p->sym_val_to_name[SYM_COMMONS];
+	if (flex_array_put_ptr(fa, comdatum->value - 1, key,
+			       GFP_KERNEL | __GFP_ZERO))
+		BUG();
 	return 0;
 }
 
@@ -267,12 +272,16 @@ static int class_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct class_datum *cladatum;
+	struct flex_array *fa;
 
 	cladatum = datum;
 	p = datap;
 	if (!cladatum->value || cladatum->value > p->p_classes.nprim)
 		return -EINVAL;
-	p->p_class_val_to_name[cladatum->value - 1] = key;
+	fa = p->sym_val_to_name[SYM_CLASSES];
+	if (flex_array_put_ptr(fa, cladatum->value - 1, key,
+			       GFP_KERNEL | __GFP_ZERO))
+		BUG();
 	p->class_val_to_struct[cladatum->value - 1] = cladatum;
 	return 0;
 }
@@ -281,6 +290,7 @@ static int role_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct role_datum *role;
+	struct flex_array *fa;
 
 	role = datum;
 	p = datap;
@@ -288,7 +298,11 @@ static int role_index(void *key, void *datum, void *datap)
 	    || role->value > p->p_roles.nprim
 	    || role->bounds > p->p_roles.nprim)
 		return -EINVAL;
-	p->p_role_val_to_name[role->value - 1] = key;
+
+	fa = p->sym_val_to_name[SYM_ROLES];
+	if (flex_array_put_ptr(fa, role->value - 1, key,
+			       GFP_KERNEL | __GFP_ZERO))
+		BUG();
 	p->role_val_to_struct[role->value - 1] = role;
 	return 0;
 }
@@ -297,6 +311,7 @@ static int type_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct type_datum *typdatum;
+	struct flex_array *fa;
 
 	typdatum = datum;
 	p = datap;
@@ -306,10 +321,13 @@ static int type_index(void *key, void *datum, void *datap)
 		    || typdatum->value > p->p_types.nprim
 		    || typdatum->bounds > p->p_types.nprim)
 			return -EINVAL;
-		p->p_type_val_to_name[typdatum->value - 1] = key;
-		/* this flex array was all preallocated, this cannot fail */
-		if (flex_array_put_ptr(p->type_val_to_struct_array,
-				       typdatum->value - 1, typdatum,
+		fa = p->sym_val_to_name[SYM_TYPES];
+		if (flex_array_put_ptr(fa, typdatum->value - 1, key,
+				       GFP_KERNEL | __GFP_ZERO))
+			BUG();
+
+		fa = p->type_val_to_struct_array;
+		if (flex_array_put_ptr(fa, typdatum->value - 1, typdatum,
 				       GFP_KERNEL | __GFP_ZERO))
 			BUG();
 	}
@@ -321,6 +339,7 @@ static int user_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct user_datum *usrdatum;
+	struct flex_array *fa;
 
 	usrdatum = datum;
 	p = datap;
@@ -328,7 +347,11 @@ static int user_index(void *key, void *datum, void *datap)
 	    || usrdatum->value > p->p_users.nprim
 	    || usrdatum->bounds > p->p_users.nprim)
 		return -EINVAL;
-	p->p_user_val_to_name[usrdatum->value - 1] = key;
+
+	fa = p->sym_val_to_name[SYM_USERS];
+	if (flex_array_put_ptr(fa, usrdatum->value - 1, key,
+			       GFP_KERNEL | __GFP_ZERO))
+		BUG();
 	p->user_val_to_struct[usrdatum->value - 1] = usrdatum;
 	return 0;
 }
@@ -337,6 +360,7 @@ static int sens_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct level_datum *levdatum;
+	struct flex_array *fa;
 
 	levdatum = datum;
 	p = datap;
@@ -345,7 +369,10 @@ static int sens_index(void *key, void *datum, void *datap)
 		if (!levdatum->level->sens ||
 		    levdatum->level->sens > p->p_levels.nprim)
 			return -EINVAL;
-		p->p_sens_val_to_name[levdatum->level->sens - 1] = key;
+		fa = p->sym_val_to_name[SYM_LEVELS];
+		if (flex_array_put_ptr(fa, levdatum->level->sens - 1, key,
+				       GFP_KERNEL | __GFP_ZERO))
+			BUG();
 	}
 
 	return 0;
@@ -355,6 +382,7 @@ static int cat_index(void *key, void *datum, void *datap)
 {
 	struct policydb *p;
 	struct cat_datum *catdatum;
+	struct flex_array *fa;
 
 	catdatum = datum;
 	p = datap;
@@ -362,7 +390,10 @@ static int cat_index(void *key, void *datum, void *datap)
 	if (!catdatum->isalias) {
 		if (!catdatum->value || catdatum->value > p->p_cats.nprim)
 			return -EINVAL;
-		p->p_cat_val_to_name[catdatum->value - 1] = key;
+		fa = p->sym_val_to_name[SYM_CATS];
+		if (flex_array_put_ptr(fa, catdatum->value - 1, key,
+				       GFP_KERNEL | __GFP_ZERO))
+			BUG();
 	}
 
 	return 0;
@@ -392,9 +423,16 @@ static int policydb_index_classes(struct policydb *p)
 	int rc;
 
 	rc = -ENOMEM;
-	p->p_common_val_to_name =
-		kmalloc(p->p_commons.nprim * sizeof(char *), GFP_KERNEL);
-	if (!p->p_common_val_to_name)
+	p->sym_val_to_name[SYM_COMMONS] = flex_array_alloc(sizeof(char *),
+							   p->p_commons.nprim,
+							   GFP_KERNEL | __GFP_ZERO);
+	if (!p->sym_val_to_name[SYM_COMMONS])
+		goto out;
+
+	rc = flex_array_prealloc(p->sym_val_to_name[SYM_COMMONS],
+				 0, p->p_commons.nprim - 1,
+				 GFP_KERNEL | __GFP_ZERO);
+	if (rc)
 		goto out;
 
 	rc = hashtab_map(p->p_commons.table, common_index, p);
@@ -408,9 +446,16 @@ static int policydb_index_classes(struct policydb *p)
 		goto out;
 
 	rc = -ENOMEM;
-	p->p_class_val_to_name =
-		kmalloc(p->p_classes.nprim * sizeof(char *), GFP_KERNEL);
-	if (!p->p_class_val_to_name)
+	p->sym_val_to_name[SYM_CLASSES] = flex_array_alloc(sizeof(char *),
+							   p->p_classes.nprim,
+							   GFP_KERNEL | __GFP_ZERO);
+	if (!p->sym_val_to_name[SYM_CLASSES])
+		goto out;
+
+	rc = flex_array_prealloc(p->sym_val_to_name[SYM_CLASSES],
+				 0, p->p_classes.nprim - 1,
+				 GFP_KERNEL | __GFP_ZERO);
+	if (rc)
 		goto out;
 
 	rc = hashtab_map(p->p_classes.table, class_index, p);
@@ -507,10 +552,18 @@ static int policydb_index_others(struct policydb *p)
 
 	for (i = SYM_ROLES; i < SYM_NUM; i++) {
 		rc = -ENOMEM;
-		p->sym_val_to_name[i] =
-			kmalloc(p->symtab[i].nprim * sizeof(char *), GFP_KERNEL);
+		p->sym_val_to_name[i] = flex_array_alloc(sizeof(char *),
+							 p->symtab[i].nprim,
+							 GFP_KERNEL | __GFP_ZERO);
 		if (!p->sym_val_to_name[i])
 			goto out;
+
+		rc = flex_array_prealloc(p->sym_val_to_name[i],
+					 0, p->symtab[i].nprim - 1,
+					 GFP_KERNEL | __GFP_ZERO);
+		if (rc)
+			goto out;
+
 		rc = hashtab_map(p->symtab[i].table, index_f[i], p);
 		if (rc)
 			goto out;
@@ -703,8 +756,10 @@ void policydb_destroy(struct policydb *p)
 		hashtab_destroy(p->symtab[i].table);
 	}
 
-	for (i = 0; i < SYM_NUM; i++)
-		kfree(p->sym_val_to_name[i]);
+	for (i = 0; i < SYM_NUM; i++) {
+		if (p->sym_val_to_name[i])
+			flex_array_free(p->sym_val_to_name[i]);
+	}
 
 	kfree(p->class_val_to_struct);
 	kfree(p->role_val_to_struct);
@@ -1566,9 +1621,9 @@ static int user_bounds_sanity_check(void *key, void *datum, void *datap)
 			printk(KERN_ERR
 			       "SELinux: boundary violated policy: "
 			       "user=%s role=%s bounds=%s\n",
-			       p->p_user_val_to_name[user->value - 1],
-			       p->p_role_val_to_name[bit],
-			       p->p_user_val_to_name[upper->value - 1]);
+			       sym_name(p, SYM_USERS, user->value - 1),
+			       sym_name(p, SYM_ROLES, bit),
+			       sym_name(p, SYM_USERS, upper->value - 1));
 
 			return -EINVAL;
 		}
@@ -1603,9 +1658,9 @@ static int role_bounds_sanity_check(void *key, void *datum, void *datap)
 			printk(KERN_ERR
 			       "SELinux: boundary violated policy: "
 			       "role=%s type=%s bounds=%s\n",
-			       p->p_role_val_to_name[role->value - 1],
-			       p->p_type_val_to_name[bit],
-			       p->p_role_val_to_name[upper->value - 1]);
+			       sym_name(p, SYM_ROLES, role->value - 1),
+			       sym_name(p, SYM_TYPES, bit),
+			       sym_name(p, SYM_ROLES, upper->value - 1));
 
 			return -EINVAL;
 		}
@@ -1637,7 +1692,7 @@ static int type_bounds_sanity_check(void *key, void *datum, void *datap)
 			printk(KERN_ERR "SELinux: type %s: "
 			       "bounded by attribute %s",
 			       (char *) key,
-			       p->p_type_val_to_name[upper->value - 1]);
+			       sym_name(p, SYM_TYPES, upper->value - 1));
 			return -EINVAL;
 		}
 	}