@wdormann@infosec.exchange As noted in the readme in the repo, the issue being exploited was already recognized in 2020. Bit of a shame it never got patched back then.
At the moment, this is solved by failing open: If the mm is gone, we pretend that it was dumpable. That's dubious from a security perspective - as one example, we drop the mm_struct before the file descriptor table, so someone might be able to steal file descriptors from an exiting tasks when dumpability was supposed to prevent that.