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From: Borislav Petkov <bp@alien8.de>
To: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Paul Menzel <pmenzel@molgen.mpg.de>,
	linux-mm@kvack.org, x86@kernel.org,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: x86/mm: Found insecure W+X mapping at address (ptrval)/0xc00a0000
Date: Thu, 4 Oct 2018 10:48:06 +0200	[thread overview]
Message-ID: <20181004084806.GC1864@zn.tnic> (raw)
In-Reply-To: <20181004084318.GB3630@8bytes.org>

On Thu, Oct 04, 2018 at 10:43:18AM +0200, Joerg Roedel wrote:
> Yeah, that's what I also found out back then, the region needs to be WX.
> So we can either leave with the warning, as we know it is harmless and
> where it comes from or implement an exception in the checking code for
> that region.

The second thing is what I'm thinking too.

Or, a 3rd: not direct-map that first range at all. Commenting out the
ISA range mapping didn't have any adverse effects on my system here, for
example. But then those other mappings appeared:

https://lkml.kernel.org/r/20181003212255.GB28361@zn.tnic

for which I have no explanation yet how they came about.

This needs to be understood fully before we do anything. But it is
32-bit so it gets preempted by more important things all the time :)

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

  reply	other threads:[~2018-10-04  8:48 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-19  6:55 x86/mm: Found insecure W+X mapping at address (ptrval)/0xc00a0000 Paul Menzel
2018-09-19  8:09 ` Thomas Gleixner
2018-09-20  7:07   ` Paul Menzel
2018-09-20 22:51     ` Thomas Gleixner
2018-09-24 21:47       ` Paul Menzel
2018-09-28 14:55         ` Thomas Gleixner
2018-10-03 21:22           ` Borislav Petkov
2018-10-04  3:11             ` Paul Menzel
2018-10-04  7:48               ` Borislav Petkov
2018-10-04  8:03             ` Joerg Roedel
2018-10-04  8:14               ` Borislav Petkov
2018-10-04  8:40                 ` Paul Menzel
2018-10-04  8:49                   ` Borislav Petkov
2018-10-04  8:59                     ` Paul Menzel
2018-10-04 10:54                       ` Borislav Petkov
2018-10-04 11:00                         ` Paul Menzel
2018-10-04 11:12                           ` Borislav Petkov
2018-10-04  8:43                 ` Joerg Roedel
2018-10-04  8:48                   ` Borislav Petkov [this message]
2018-10-05  9:27               ` Thomas Gleixner
2018-10-05  9:39                 ` Paul Menzel
2018-10-08 19:37                   ` Thomas Gleixner
2018-10-08 20:08                     ` Bjorn Helgaas

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