lkml.org 
[lkml]   [2014]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] arm: don't allow CONFIG_DEBUG_SET_MODULE_RONX if CONFIG_JUMP_LABEL is enabled
On 4/1/2014 3:04 AM, Alexander Holler wrote:
> CONFIG_DEBUG_SET_MODULE_RONX sounds like a nice security feature, but
> things might fail late (and unexpected) if module code is set to read-only
> while CONFIG_JUMP_LABEL is enabled (e.g. modprobe bridge).
>
> Avoid this.
>
> Signed-off-by: Alexander Holler <holler@ahsoftware.de>
> ---
> arch/arm/Kconfig.debug | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
> index 0531da8..6627b9e 100644
> --- a/arch/arm/Kconfig.debug
> +++ b/arch/arm/Kconfig.debug
> @@ -1197,7 +1197,7 @@ config PID_IN_CONTEXTIDR
>
> config DEBUG_SET_MODULE_RONX
> bool "Set loadable kernel module data as NX and text as RO"
> - depends on MODULES
> + depends on MODULES && !JUMP_LABEL
> ---help---
> This option helps catch unintended modifications to loadable
> kernel module's text and read-only data. It also prevents execution
>

Kees Cook has something similar[1] for not-module space as well, we probably want
this there as well. A shame we keep finding reasons these features will be turned
off. Looks good to me otherwise.

Laura

[1]http://lists.infradead.org/pipermail/linux-arm-kernel/2014-February/232644.html

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation


\
 
 \ /
  Last update: 2014-04-01 20:41    [W:0.073 / U:0.784 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site