selinux: factor out loop body from filename_trans_read()

It simplifies cleanup in the error path. This will be extra useful in
later patch.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/policydb.c

@@ -1880,31 +1880,18 @@ static int range_read(struct policydb *p, void *fp)
 	return rc;
 }
 
-static int filename_trans_read(struct policydb *p, void *fp)
+static int filename_trans_read_one(struct policydb *p, void *fp)
 {
 	struct filename_trans *ft;
-	struct filename_trans_datum *otype;
-	char *name;
-	u32 nel, len;
+	struct filename_trans_datum *otype = NULL;
+	char *name = NULL;
+	u32 len;
 	__le32 buf[4];
-	int rc, i;
-
-	if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS)
-		return 0;
-
-	rc = next_entry(buf, fp, sizeof(u32));
-	if (rc)
-		return rc;
-	nel = le32_to_cpu(buf[0]);
-
-	for (i = 0; i < nel; i++) {
-		otype = NULL;
-		name = NULL;
+	int rc;
 
-		rc = -ENOMEM;
 	ft = kzalloc(sizeof(*ft), GFP_KERNEL);
 	if (!ft)
-			goto out;
+		return -ENOMEM;
 
 	rc = -ENOMEM;
 	otype = kmalloc(sizeof(*otype), GFP_KERNEL);
@@ -1944,22 +1931,39 @@ static int filename_trans_read(struct policydb *p, void *fp)
 		 * Do not return -EEXIST to the caller, or the system
 		 * will not boot.
 		 */
-			if (rc != -EEXIST)
+		if (rc == -EEXIST)
+			rc = 0;
 		goto out;
-			/* But free memory to avoid memory leak. */
-			kfree(ft);
-			kfree(name);
-			kfree(otype);
-		}
 	}
-	hash_eval(p->filename_trans, "filenametr");
 	return 0;
 out:
 	kfree(ft);
 	kfree(name);
 	kfree(otype);
+	return rc;
+}
+
+static int filename_trans_read(struct policydb *p, void *fp)
+{
+	u32 nel;
+	__le32 buf[1];
+	int rc, i;
+
+	if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS)
+		return 0;
 
+	rc = next_entry(buf, fp, sizeof(u32));
+	if (rc)
 		return rc;
+	nel = le32_to_cpu(buf[0]);
+
+	for (i = 0; i < nel; i++) {
+		rc = filename_trans_read_one(p, fp);
+		if (rc)
+			return rc;
+	}
+	hash_eval(p->filename_trans, "filenametr");
+	return 0;
 }
 
 static int genfs_read(struct policydb *p, void *fp)