On Friday, 30 October 2026 14:51:01 Central European Standard Time Richard W.M. Jones via devel wrote: > On Thu, Oct 29, 2026 at 12:54:54PM +0100, Fabio Valentini wrote: > > > 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. > > > It's things like, does the runtime detect when it is being run as SUID > and clean out / refuse to use environment variables (such as > LD_PRELOAD). A lot of this comes from the C library, so if Rust is > using glibc then that's a good start, but I guess the language itself > (or more likely, Rust-specific libraries) might require attention too.
See https://gitlab.com/cryptomilk/usermode/-/blob/main/crates/userhelper/src/ env.rs?ref_type=heads which is exactly about that. > As Florian hinted, a great deal of this is unwritten knowledge and/or > learnings from decades of security incidents. Yes, and if you compare my implementation with the usermode written in C you will C that it is a lot stricter in a lot of things. There is also "GCONV_PATH", "LOCPATH" and "NLSPATH" not only "LD_*". Review is welcome. Best regards Andreas -- _______________________________________________ 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
