[ongy]

The specific way sshd was infected would not have happened with libxz as dlopen library.

Debian's sshd only uses libsystemd for the notify api. I.e. it doesn't need any feature that uses libxz. If it's dlopen()ed, it does not need to be loaded into the process context to use an unrelated feature.

FWIW, IMO upstream systemd should split their monolithic library and allow users to pick better that way, but this has other implications on DX.

[Tuna-Fish]

> FWIW, IMO upstream systemd should split their monolithic library and allow users to pick better that way, but this has other implications on DX.

FWIW, upstream systemd has the opinion that no-one should load the library for startup notification, instead they should use the well documented api and just write a message to a socket.

[idoubtit]

Indeed, that's what the Debian maintainer of OpenSSH did soon after the quick security fix. He replaced the dependency on libsystemd with some hand-made code that notifies systemd by socket. https://salsa.debian.org/ssh-team/openssh/-/commit/cc5f37cb8...

[ptx]

That's not what they said in their update to the documentation[0] last week, which says that "although using libsystemd is a good choice, this protocol can also be reimplemented without external dependencies".

It calls it a "good choice". Did they say somewhere else that no-one should do it despite it supposedly being a good choice?

[0] https://github.com/systemd/systemd/pull/32030/files

[klooney]

Yes- https://mastodon.social/@pid_eins/112202696589971319

[newpavlov]

sshd should not have used libsystemd in the first place for the trivial notification. And the ifunc stuff is its own security nightmare. Papering over this by dlopen-ing some libs in libsystemd does not address the deeper issues.

[NewJazz]

FWIW, IMO upstream systemd should split their monolithic library and allow users to pick better that way, but this has other implications on DX.

They've done the exact opposite afaict. Libsysd used to be split up, now it is monolithic.

[marcosdumay]

Upstream systemd should just cut the unused crap from their notification protocol and promise it's stable.

They probably couldn't change it anymore if they tried to.

[Denvercoder9]

The systemd notification protocol has been stable and documented as such for years (probably even a decade at this point): https://systemd.io/PORTABILITY_AND_STABILITY/

[klooney]

The whole protocol is "write READY=1 to the socket found in the NOTIFY_SOCKET environment variable".