If the target 'tmp' directory (specified by java.io.tmpdir) used by Camel, does not have proper privileges, then Camel enters infinite loop. The offending code is found in org.apache.camel.util.FileUtil.createNewTempDir().

while (!f.mkdir()) {
    x = ran.nextInt(1000000);
    f = new File(s, "camel-tmp-" + x);
}

Refer to the f.can*() methods prior to entering the loop.