On the removal of nscd from Fedora, and the future of nscd.

DJ Delorie dj@redhat.com
Tue Mar 1 16:54:02 GMT 2022


Ludovic Courts <ludo@gnu.org> writes:
> This nscd requirement is one of the few must-haves to ensure, as
> Joseph writes, that processes (in particular those linked against
> Guix’s libc) do not end up dlopening arbitrary, possibly incompatible
> libraries.

My point is, if there's a risk that a Guix binary *could* load a host
dso, then Guix is insufficiently isolated from the host system.  nscd is
just one example of how this could happen.  If you accept this
non-isolation, you need to accept that dsos need to be cross-usable.

That Guix is accepting some sharing (like /etc/nsswitch.conf) but not
all sharing (like libnss_*.so) opens Guix up to these types of problems,
and thus, the onus is mostly on Guix to deal with them.

Hence my feeling that "keep ncsd around because we're not isolated
enough" is a weak (but still valid) reason to keep nscd.  nscd is just
the most obvious problem point, but not the only problem point.  The
right solution is to complete the isolation, although I admit that may
be an impossible goal at this point.

Note that I don't feel strongly about the above; just pointing it out.



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