* Fabio Valentini: > On Wed, Oct 28, 2026 at 6:47 PM Florian Weimer via devel > <[email protected]> wrote: >> >> * Aoife Moloney via devel-announce: >> >> > The privilege-separated design is preserved and sharpened: the only >> > setuid-root binary is `userhelper`, kept to PAM calls, privilege >> > transitions, and `exec`. >> >> It his binary written in Rust? >> >> The upstream Rust security team has not documented that Rust is safe to >> use in SUID binaries, and the standard library (and therefore most >> crates) do not take this special operating environment into >> consideration. > > Can you elaborate what you mean here? I don't really see a connection > between programming language and SUID use. And I don't see how the > Rust standard library plays any role here either - it contains zero > functionality related to unix user / group support.
The connection is that the language implementations in Fedora (specifically their run-time components) may make assumptions about the trustworthiness of the execution environment. Typical examples of things that could be problematic for SUID binaries: obtaining log file paths from the process environment, automatically loading code based on environment variables or files in the user's home directory, honoring umask when creating files, automatically writing crash dumps (whether in the current directory or elsewhere), providing a special syntax for command line arguments that are processed by the runtime instead of the application. If the language runtime does this, it may create impossible-to-fix vulnerabilities if the binaries are made SUID. (Of course, this is where usermode comes in.) Thanks, Florian -- _______________________________________________ devel mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected] Do not reply to spam, report it: https://forge.fedoraproject.org/infra/tickets/issues/new
