Disable calling functions in transitive dependencies, force them to be direct dependencies.
Why should sshd be allowed to call an xz function directly without xz being an immediate dependency.
I'm not sure what all that would entail with the ifunc stuff, but I remember encountering a glibc linking change moving from Red Hat 6 to RH7 that did something similar and broke the build process for some legacy code.
No. They couldn't get along with the idea that some open source software packages should also sometimes be cut away, just like all other packages.
They felt threatened by the idea that open source maintenance can ever go wrong and started attacking me. They argued closed source was worse.
That was not my point at all. I was not raising a weakness of open source. I was just pointing out that linking to libsystemd had that kind of problem.
Still the question remains: what technology could be implemented to mitigate this type of attack (beyond sshd)?
For example, Linux sandboxing is poor, and SeLinux is not usually enforced.