linux-kernel - Re: Reading /dev/mem by dd

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <20091112212935.GE5728@lenovo>
Date:	Fri, 13 Nov 2009 00:29:35 +0300
From:	Cyrill Gorcunov <gorcunov@...il.com>
To:	Krzysztof Halasa <khc@...waw.pl>
Cc:	Henrique de Moraes Holschuh <hmh@....eng.br>,
	Andi Kleen <andi@...stfloor.org>,
	Robert Hancock <hancockrwd@...il.com>,
	"Anton D. Kachalov" <mouse@...c.ru>, linux-kernel@...r.kernel.org
Subject: Re: Reading /dev/mem by dd

On Thu, Nov 12, 2009 at 10:07:22PM +0100, Krzysztof Halasa wrote:
> "Henrique de Moraes Holschuh" <hmh@....eng.br> writes:
> 
> > In this case, the problem seems to be access over /dev/mem to stuff the
> > kernel is already taking care of.
> 
> Not sure if local APIC counts as "PCI space and the BIOS code and data
> regions" but:
> 
> $ grep STRICT_DEVMEM -A 15 arch/x86/Kconfig.debug
> config STRICT_DEVMEM
>         bool "Filter access to /dev/mem"
>         ---help---
> 

Yes, having this option turned on an access to LAPIC/IO_APIC
space will be forbidden.

	-- Cyrill
--
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/