On Tue, May 28, 2019 at 10:37:10AM +0800, Dianzhang Chen wrote: > Hi, > Because when i reply your email,i always get 'Message rejected' from > gmail(get this rejection from all the recipients). I still don't know > how to deal with it, so i reply your email here:
Hi! This is weird. Next time simply reply to LKML (I CC'ed it back). > Because of speculative execution, the attacker can bypass the bound > check `if (resource >= RLIM_NLIMITS)`. And then misprediction get detected and execution is dropped. So I still don't see a problem here, since we don't leak info even in such case. That said I don't mind for this patch but rather in a sake of code clarity, not because of spectre issue since it has nothing to do here. > as for array_index_nospec(index, size), it will clamp the index within > the range of [0, size), and attacker can't exploit speculative > execution to make the index out of range [0, size). > > > For more detail, please check the link below: > > https://github.com/torvalds/linux/commit/f3804203306e098dae9ca51540fcd5eb700d7f40