On Tue, Feb 24, 2015 at 3:01 PM, H. Peter Anvin <[email protected]> wrote: > On 02/24/2015 02:56 PM, Andy Lutomirski wrote: >> On Tue, Feb 24, 2015 at 2:52 PM, H. Peter Anvin <[email protected]> wrote: >>> On 02/24/2015 02:25 PM, Andy Lutomirski wrote: >>>> On Tue, Feb 24, 2015 at 10:51 AM, Denys Vlasenko <[email protected]> >>>> wrote: >>>>> In all three 32-bit entry points, %eax is zero-extended to %rax. >>>>> It is safe to do 32-bit compare when checking that syscall# >>>>> is not too large. >>>> >>>> Applied. Thanks! >>>> >>> >>> NAK NAK NAK NAK NAK!!!! >>> >>> We have already had this turn into a security issue not just once but >>> TWICE, because someone decided to "optimize" the path by taking out the >>> zero extend. >>> >>> The use of a 64-bit compare here is an intentional "belts and >>> suspenders" safety issue. >> >> Fair enough. OK if I just undo that part of this patch? >> > > Actually this part should have been broken up. The word "several" in > the patch description is by itself a cause to NAK the patch.
Point taken. Denys, can you fix this and send a v2 of the entire series with the traps.c fix as well? Thanks, Andy > > -hpa > > -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
