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From: Matthew Garrett <matthew.garrett@nebula.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
	"keescook@chromium.org" <keescook@chromium.org>,
	"hpa@zytor.com" <hpa@zytor.com>
Subject: Re: [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions
Date: Sun, 8 Sep 2013 14:40:04 +0000	[thread overview]
Message-ID: <1378651204.2300.7.camel@x230> (raw)
In-Reply-To: <20130908072408.GA5092@kroah.com>

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On Sun, 2013-09-08 at 00:24 -0700, Greg KH wrote:
> On Sun, Sep 08, 2013 at 06:44:08AM +0000, Matthew Garrett wrote:

> > At the most trivial level, grab the address of sig_enforce from
> > kallsyms, jump to a kernel that doesn't enforce STRICT_DEVMEM, modify
> > sig_enforce, jump back to the old kernel.
> 
> Which proves what?

sig_enforce can be set, but once it's set can't be unset. Why do you
think that is?

-- 
Matthew Garrett <matthew.garrett@nebula.com>
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  reply	other threads:[~2013-09-08 14:40 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-03 23:50 Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 01/11] Add secure_modules() call Matthew Garrett
2013-09-04  0:45   ` James Morris
2013-09-05  2:14   ` joeyli
2013-09-03 23:50 ` [PATCH V3 02/11] PCI: Lock down BAR access when module security is enabled Matthew Garrett
2013-09-04  0:45   ` James Morris
2013-09-04 16:57   ` David Woodhouse
2013-09-04 17:04     ` Matthew Garrett
2013-09-04 18:58       ` David Woodhouse
2013-09-04 19:01         ` Matthew Garrett
2013-09-04 19:31           ` David Woodhouse
2013-09-03 23:50 ` [PATCH V3 03/11] x86: Lock down IO port " Matthew Garrett
2013-09-04  0:45   ` James Morris
2013-09-05  3:52   ` H. Peter Anvin
2013-09-05  3:58     ` Matthew Garrett
2013-09-05 15:36       ` H. Peter Anvin
2013-09-03 23:50 ` [PATCH V3 04/11] ACPI: Limit access to custom_method Matthew Garrett
2013-09-04  0:46   ` James Morris
2013-09-03 23:50 ` [PATCH V3 05/11] asus-wmi: Restrict debugfs interface when module loading is restricted Matthew Garrett
2013-09-04  0:46   ` James Morris
2013-09-03 23:50 ` [PATCH V3 06/11] Restrict /dev/mem and /dev/kmem " Matthew Garrett
2013-09-04  0:47   ` James Morris
2013-09-03 23:50 ` [PATCH V3 07/11] acpi: Ignore acpi_rsdp kernel parameter " Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions Matthew Garrett
2013-09-04  0:48   ` James Morris
2013-09-04 20:09   ` jerry.hoemann
2013-09-04 20:12     ` Matthew Garrett
2013-09-04 20:14     ` Josh Boyer
2013-09-08  6:40   ` Greg KH
2013-09-08  6:44     ` Matthew Garrett
2013-09-08  7:24       ` Greg KH
2013-09-08 14:40         ` Matthew Garrett [this message]
2013-09-08 15:51         ` Kees Cook
2013-09-08 16:18           ` Greg KH
2013-09-08 16:24             ` Matthew Garrett
2013-09-08 16:39               ` Greg KH
2013-09-08 16:59                 ` Matthew Garrett
2013-09-08 17:22                   ` Greg KH
2013-09-08 17:25                     ` Matthew Garrett
2013-09-08 17:11           ` James Bottomley
2013-09-08 17:15             ` Matthew Garrett
2013-09-08 17:22               ` James Bottomley
2013-09-08 17:27                 ` Matthew Garrett
2013-09-08 17:32                   ` James Bottomley
2013-09-08 17:38                     ` Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 09/11] uswsusp: Disable when module loading is restricted Matthew Garrett
2013-09-04  0:48   ` James Morris
2013-09-05  3:20   ` joeyli
2013-09-03 23:50 ` [PATCH V3 10/11] x86: Restrict MSR access " Matthew Garrett
2013-09-04  0:49   ` James Morris
2013-09-03 23:50 ` [PATCH V3 11/11] Add option to automatically enforce module signatures when in Secure Boot mode Matthew Garrett
2013-09-04  1:42   ` James Morris
2013-09-04  1:42     ` Matthew Garrett
2013-09-05  3:13   ` joeyli
2013-09-05  8:24   ` joeyli
2013-09-05 10:16   ` Matt Fleming
2013-09-05 12:54     ` Matthew Garrett
2013-09-04 15:53 ` Kees Cook
2013-09-04 16:05   ` Re: Josh Boyer

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