On Fri, May 17, 2024 at 02:26:47AM +0100, Al Viro wrote: > On Fri, May 17, 2024 at 02:13:22AM +0100, Matthew Wilcox wrote: > > On Fri, May 17, 2024 at 12:29:06AM +0000, Justin Stitt wrote: > > > When running syzkaller with the newly reintroduced signed integer > > > overflow sanitizer we encounter this report: > > > > why do you keep saying it's unintentional? it's clearly intended. > > Because they are short on actual bugs to be found by their tooling > and attempt to inflate the sound/noise rate; therefore, every time "short on bugs"? We're trying to drive it to zero. I would *love* to be short on bugs. See my reply[1] to Ted. > when overflow _IS_ handled correctly, it must have been an accident - > we couldn't have possibly done the analysis correctly. And if somebody > insists that they _are_ capable of basic math, they must be dishonest. > So... "unintentional" it's going to be. As Justin said, this is a poor choice in wording. In other cases I've tried to describe this as making changes so that intent is unambiguous (to both a human and a compiler). > <southpark> Math is hard, mmkay? </southpark> > > Al, more than slightly annoyed by that aspect of the entire thing... I'm sorry about that. None of this is a commentary on code correctness; we're just trying to refactor things so that the compiler can help us catch the _unintended_ overflows. This one is _intended_, so here we are to find a palatable way to leave the behavior unchanged while gaining compiler coverage. -Kees [1] https://lore.kernel.org/linux-hardening/202405171329.019F2F566C@keescook/ -- Kees Cook
