linux-kernel - Re: [PATCH 3.19 3/3] x86, mpx: Change the MPX enable/disable API to arch

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 7 Jan 2015 15:24:52 -0800
From:	Andy Lutomirski <luto@...capital.net>
To:	Dave Hansen <dave.hansen@...ux.intel.com>
Cc:	Andi Kleen <andi@...stfloor.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	X86 ML <x86@...nel.org>, Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 3.19 3/3] x86, mpx: Change the MPX enable/disable API to arch_prctl

On Wed, Jan 7, 2015 at 3:18 PM, Dave Hansen <dave.hansen@...ux.intel.com> wrote:
> On 01/05/2015 03:04 PM, Andy Lutomirski wrote:
>> Anyway, if it's actually a problem to change it, I have no real
>> problem keeping it, but I think we *really* need to validate the rest
>> of the arguments at the very least.
>
> If we "validate" the arguments like you suggested, then a call like this:
>
>         prctl(PR_MPX_DISABLE_MANAGEMENT);
>
> ends up returning -EINVAL:
>
>> prctl(0x2b /* PR_??? */, 0x7fffffd3, 0x7f360955e9e0, 0x2c, 0x7f3609314840) = -1 EINVAL (Invalid argument)
>
> A quick grep through ltp and some other source I have laying around does
> *not* show folks adding 0's to these calls for "empty" arguments.  Is
> this really something we want to do?
>
>         prctl(PR_MPX_DISABLE_MANAGEMENT, 0, 0, 0, 0);

Yes, because we might want to do prctl(PR_MPX_ENABLE_MANAGEMENT, x, y,
z, 0) some day.

--Andy

-- 
Andy Lutomirski
AMA Capital Management, LLC
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/