As always with these admirable hacks, I feel compelled to point out these are not really ELF executables but just small files you can trick the x86_64 Linux kernel into loading.
I mean they're very clever and legit and kudos to the people who develop these exploits, but they're not ELF.
Is it really not ELF? The file starts with the \x7FELF magic, but I'm not by my laptop to see what `file btry` outputs.
GP is likely referring to how fields in the ELF and program header are abused for instructions and data in a way that happens to not break things on Linux.
I'd agree it's not standards compliant. But if it's accepted as an ELF by Linux, in what way is it not an ELF?
Or to flip it round. If Linux accepts something as an ELF that isn't, then it isn't an ELF loader.
Would you describe a web browser that doesn't score 100% on a rendering test as not a browser?