On Thu, Jan 25, 2018 at 2:34 PM, Alan Cox <gno...@lxorguk.ukuu.org.uk> wrote: > As you observe any attacker can already trivially ascertain whether > protection is on, so there is no point pretending file permissions > magically stop that. In fact the information is already in cpuinfo.
Actually the other place it leaks is in dmesg, which would need to be patched too. My understanding about cpuinfo was that it showed whether or not the processor family is generally vulnerable to it, independent of whether or not the kernel has been patched. What this patch does relates to whether or not the kernel has been patched.