diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index dc12fd0de1c2..c8cb407482c6 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -424,7 +424,7 @@ err:
 
 int parse_num_list(const char *s, struct test_selector *sel)
 {
-	int i, set_len = 0, num, start = 0, end = -1;
+	int i, set_len = 0, new_len, num, start = 0, end = -1;
 	bool *set = NULL, *tmp, parsing_end = false;
 	char *next;
 
@@ -459,18 +459,19 @@ int parse_num_list(const char *s, struct test_selector *sel)
 			return -EINVAL;
 
 		if (end + 1 > set_len) {
-			set_len = end + 1;
-			tmp = realloc(set, set_len);
+			new_len = end + 1;
+			tmp = realloc(set, new_len);
 			if (!tmp) {
 				free(set);
 				return -ENOMEM;
 			}
+			for (i = set_len; i < start; i++)
+				tmp[i] = false;
 			set = tmp;
+			set_len = new_len;
 		}
-		for (i = start; i <= end; i++) {
+		for (i = start; i <= end; i++)
 			set[i] = true;
-		}
-
 	}
 
 	if (!set)