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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: Kees Cook <keescook@chromium.org>, Borislav Petkov <bp@alien8.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        lkml <linux-kernel@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Andy Lutomirski <luto@kernel.org>, Brian Gerst <brgerst@gmail.com>,
        Denys Vlasenko <dvlasenk@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        Linux PM list <linux-pm@vger.kernel.org>,
        Stephen Smalley <sds@tycho.nsa.gov>
Subject: Re: [PATCH v3] x86/power/64: Fix kernel text mapping corruption during image restoration
Date: Thu, 30 Jun 2016 04:20:43 +0200
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On Wednesday, June 29, 2016 07:52:18 PM Logan Gunthorpe wrote:
> Hey Raf,
> 
> Sorry to report that although the patch works the majority of the time, 
> I just got a suspicious kernel panic during resume.
> 
> It said:
> 
> "kernel tried to execute NX protected page - exploit attempt? (uid: 0)"
> 
> You can find a photo of the panic here:
> 
> http://staff.deltatee.com/~logang/panic.jpg

Thanks for the report!

That's not what Boris was seeing at least.

It looks like clearing the NX bit for relocated_restore_code in
relocate_restore_code() didn't work for some reason.

I don't see why it may not work ATM, I need to have a fresh look at that
tomorrow.

I had hoped to be able to fix this bug for 4.7, but it looks like it will
miss the mark after all.  Oh well.

Thanks,
Rafael