--- babeltrace-1.5.8/formats/ctf/ctf.c.orig	2020-10-23 11:45:34.351789250 -0700
+++ babeltrace-1.5.8/formats/ctf/ctf.c	2020-10-23 12:16:24.236460342 -0700
@@ -2191,7 +2191,7 @@
 	struct stat statbuf;
 	char *index_name;
 
-	fd = openat(td->dirfd, path, flags);
+	fd = openat(td->dirfd, path, flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 	if (fd < 0) {
 		perror("File stream openat()");
 		ret = fd;
@@ -2265,7 +2265,8 @@
 			goto error_index;
 		}
 	} else {
-		ret = openat(td->dirfd, index_name, flags);
+		ret = openat(td->dirfd, index_name, flags,
+				S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 		if (ret < 0) {
 			perror("Index file openat()");
 			ret = -1;