From: "H. Peter Anvin" <hpa@zytor.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
security@kernel.org, "Luck, Tony" <tony.luck@intel.com>,
James Morris <jmorris@namei.org>,
Mike Waychison <mikew@google.com>,
Michael Davidson <md@google.com>,
linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Mathias Krause <minipli@googlemail.com>,
Roland McGrath <roland@redhat.com>
Subject: Re: [Security] DoS on x86_64
Date: Thu, 28 Jan 2010 15:27:04 -0800 [thread overview]
Message-ID: <4B621D48.4090203@zytor.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1001281507080.3846@localhost.localdomain>
On 01/28/2010 03:09 PM, Linus Torvalds wrote:
>
>
> On Thu, 28 Jan 2010, H. Peter Anvin wrote:
>>
>> So this patch, *plus* removing any delayed side effects from
>> SET_PERSONALITY() [e.g. the TIF_ABI_PENDING stuff in x86-64 which is
>> intended to have a forward action from SET_PERSONALITY() to
>> flush_thread()] might just work. I will try it out.
>
> Yeah, if you do that, then my "split up" patch isn't necessary. And it
> would make the code a whole lot more straightforward, and remove that
> whole crazy TIF_ABI_PENDING thing.
>
> Getting rid of the whole TIF_ABI_PENDING crap would be wonderful. It would
> make SET_PERSONALITY() (and flush_thread()) way more obvious.
>
> So that would be much better than the untested "split up flush_old_exec"
> patch I just sent out. So forget that patch, and let's go with your
> further cleanup approach instead.
>
I think your splitup patch might still be a good idea in the sense that
your flush_old_exec() is the parts that can fail.
So I think the splitup patch, plus removing delayed effects, might be
the right thing to do? Testing that approach now...
-hpa
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next prev parent reply other threads:[~2010-01-28 23:27 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-28 7:34 Mathias Krause
2010-01-28 8:18 ` [Security] " Andrew Morton
2010-01-28 15:41 ` H. Peter Anvin
2010-01-28 22:33 ` Linus Torvalds
2010-01-28 22:47 ` Mathias Krause
2010-01-28 22:47 ` H. Peter Anvin
2010-01-28 23:09 ` Linus Torvalds
2010-01-28 23:27 ` H. Peter Anvin [this message]
2010-01-28 23:46 ` Linus Torvalds
2010-01-29 4:43 ` Linus Torvalds
2010-01-29 4:43 ` [PATCH 1/2] Split 'flush_old_exec' into two functions Linus Torvalds
2010-01-29 4:47 ` [PATCH 2/2] x86: get rid of the insane TIF_ABI_PENDING bit Linus Torvalds
2010-01-29 5:17 ` [PATCH 1/2] Split 'flush_old_exec' into two functions H. Peter Anvin
2010-01-29 5:05 ` [Security] DoS on x86_64 H. Peter Anvin
2010-01-29 5:29 ` H. Peter Anvin
2010-01-29 5:34 ` [PATCH 1/2] Split 'flush_old_exec' into two functions H. Peter Anvin
2010-01-29 5:34 ` [PATCH 2/2] x86: get rid of the insane TIF_ABI_PENDING bit H. Peter Anvin
2010-01-29 5:36 ` [PATCH 1/2] Split 'flush_old_exec' into two functions H. Peter Anvin
2010-01-29 5:36 ` [PATCH 2/2] x86: get rid of the insane TIF_ABI_PENDING bit H. Peter Anvin
2010-01-29 5:41 ` [PATCH 1/2] Split 'flush_old_exec' into two functions H. Peter Anvin
2010-01-29 5:41 ` [PATCH 2/2] x86: get rid of the insane TIF_ABI_PENDING bit H. Peter Anvin
2010-01-29 5:44 ` H. Peter Anvin
2010-01-29 6:14 ` [PATCH 1/2] Split 'flush_old_exec' into two functions H. Peter Anvin
2010-01-29 6:14 ` [PATCH 2/2] x86: get rid of the insane TIF_ABI_PENDING bit H. Peter Anvin
2010-01-28 23:06 ` [Security] DoS on x86_64 Linus Torvalds
2010-01-28 23:14 ` H. Peter Anvin
2010-01-28 21:31 ` Mathias Krause
2010-01-28 17:10 ` Linus Torvalds
2010-01-28 21:49 ` Mathias Krause
2010-01-28 21:58 ` Linus Torvalds
2010-01-28 22:08 ` Mathias Krause
2010-01-28 22:18 ` Linus Torvalds
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