Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending

H. Peter Anvin
2008-03-03T17:51:03Z

Pavel Machek wrote:
> On Mon 2008-03-03 09:10:35, H. Peter Anvin wrote:
>> Pavel Machek wrote:
>>>> The only thing I don't understand is why this is suddenly a problem with
>>>> 2.6.25, and not with 2.6.24? Is there a bug in 2.6.24 and previously
>>>> that allows real-mode execution of non-executable pages?
>>> It is strange indeed... Should it be traced as an regression?
>> I'd like to understand what the heck happened, but as far as we can observe
>> right now, it's a *progression*, not a regression, since executing out of a
>> non-PROT_EXEC area isn't *supposed* to work...
>
> Okay, I guess this depends on the eye of the beholder... because s2ram
> *is* supposed to work ;-).
>
> Ideally, I'd like to keep 2.6.24 behaviour for at least a while, so we
> can try to fix the libx86 out there or something...
> Pavel
> PS: Matthew, there's problem in libx86: it tries to execute from area
> not marked as PROT_EXEC.

Allowing execution of a PROT_EXEC area is a security hole. The fact
that you happened to benefit from it doesn't change its nature as a
security hole.

-hpa