On Tue, 14 May 2024 at 15:48, Theo de Raadt deraadt@openbsd.org wrote:
and can't imagine it affecting a single application
Honestly, that's the reason for not caring.
You have to do actively wrong things for this to matter AT ALL.
So no, we're not making gratuitous changes for stupid reasons.
I worry that the non-atomicity will one day be used by an attacker.
Blah blah blah. That's a made-up scare tactic if I ever heard one. It's unworthy of you.
Anybody who does mprotect/mmap/munmap/whatever over multiple independent memory mappings had better know exactly what mappings they are touching. Otherwise they are *already* just doing random crap.
In other words: nobody actually does that. Yes, you have people who first carve out one big area with an mmap(), and then do their own memory management within that area. But the point is, they are very much in control and if they do something inconsistent, they absolutely only have themselves to blame.
And if you have some app that randomly does mprotect etc over multipl memory mappings that it doesn't know what the f*^% they are, then there is no saving such a piece of unbelievable garbahe.
So stop the pointless fear-mongering. Linux does the smart thing, which is to not waste a single cycle on something that cannot possibly be relevant.
Linus