On Fri, Jul 25, 2014 at 11:30:48AM -0700, Andy Lutomirski wrote: > There is recent interest in having a way to turn generally-available > kernel features off. Maybe we should add a good one so we can stop > bikeshedding and avoid proliferating dumb interfaces. > > Things that might want to be turn-off-able include: > - getrandom with GRND_RANDOM [from the getrandom threads] > - Any lookup of a non-self pid [from the capsicum thread] > - Any lookup of a pid outside the caller thread group [capsicum] > - Various architectural things (personal wishlist), e.g.: > - RDTSC and userspace HPET access > - CPUID? > - 32-bit GDT code segments [huge attack surface] > - 64-bit GDT code segments [probably pointless] I'm not sure there's value in disabling cpuid dev interface, when the instruction is unprivileged. > I would propose a new syscall for this: > > long restrict_userspace(int mode, int type, int value, int flags); do the restrictions happen system-wide like in say SELinux, or only within the calling process, like seccomp ? Dave -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
