linux-kernel - Re: [PATCH] lkdtm: add test for executing .rodata

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

Message-ID: <56CB97EE.29381.17824260@pageexec.freemail.hu>
Date:	Tue, 23 Feb 2016 00:21:18 +0100
From:	"PaX Team" <pageexec@...email.hu>
To:	Kees Cook <keescook@...omium.org>
CC:	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	Laura Abbott <labbott@...hat.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Mark Rutland <mark.rutland@....com>,
	Jeremy Linton <jeremy.linton@....com>,
	Arnd Bergmann <arnd@...db.de>,
	"kernel-hardening@...ts.openwall.com" 
	<kernel-hardening@...ts.openwall.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] lkdtm: add test for executing .rodata

On 22 Feb 2016 at 12:46, Kees Cook wrote:

> GCC really wants to declare the section. :(

hmm, i see, so how about going about it another way. instead of trying
to do this at compile/link time, do it an load/runtime. one way of doing
it would be to preserve a page in .rodata then map in a code page underneath
that holds your empty function (which you can generate from C). it'd be
somewhat similar to how the vsyscall page on amd64 is mapped (or used to
be mapped) from the kernel image into its userland visible place.