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From: Will Deacon <will.deacon@arm.com>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com,
	Mark Rutland <mark.rutland@arm.com>,
	Laura Abbott <labbott@redhat.com>,
	x86@kernel.org
Subject: [kernel-hardening] Re: [PATCH] Kconfig: Make STRICT_DEVMEM default-y on x86 and arm64
Date: Mon, 4 Dec 2017 15:56:10 +0000	[thread overview]
Message-ID: <20171204155610.GH29619@arm.com> (raw)
In-Reply-To: <20171201201000.GA44539@beast>

On Fri, Dec 01, 2017 at 12:10:00PM -0800, Kees Cook wrote:
> Distros have been shipping with CONFIG_STRICT_DEVMEM=y for years now. It
> is probably time to flip this default for x86 and arm64.

Should we be defaulting IO_STRICT_DEVMEM on as well?

Will

> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  lib/Kconfig.debug | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 947d3e2ed5c2..39b123d04a36 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1985,7 +1985,7 @@ config STRICT_DEVMEM
>  	bool "Filter access to /dev/mem"
>  	depends on MMU && DEVMEM
>  	depends on ARCH_HAS_DEVMEM_IS_ALLOWED
> -	default y if TILE || PPC
> +	default y if TILE || PPC || X86 || ARM64
>  	---help---
>  	  If this option is disabled, you allow userspace (root) access to all
>  	  of memory, including kernel and userspace memory. Accidental
> -- 
> 2.7.4
> 
> 
> -- 
> Kees Cook
> Pixel Security

WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com,
	Mark Rutland <mark.rutland@arm.com>,
	Laura Abbott <labbott@redhat.com>,
	x86@kernel.org
Subject: Re: [PATCH] Kconfig: Make STRICT_DEVMEM default-y on x86 and arm64
Date: Mon, 4 Dec 2017 15:56:10 +0000	[thread overview]
Message-ID: <20171204155610.GH29619@arm.com> (raw)
In-Reply-To: <20171201201000.GA44539@beast>

On Fri, Dec 01, 2017 at 12:10:00PM -0800, Kees Cook wrote:
> Distros have been shipping with CONFIG_STRICT_DEVMEM=y for years now. It
> is probably time to flip this default for x86 and arm64.

Should we be defaulting IO_STRICT_DEVMEM on as well?

Will

> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  lib/Kconfig.debug | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 947d3e2ed5c2..39b123d04a36 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1985,7 +1985,7 @@ config STRICT_DEVMEM
>  	bool "Filter access to /dev/mem"
>  	depends on MMU && DEVMEM
>  	depends on ARCH_HAS_DEVMEM_IS_ALLOWED
> -	default y if TILE || PPC
> +	default y if TILE || PPC || X86 || ARM64
>  	---help---
>  	  If this option is disabled, you allow userspace (root) access to all
>  	  of memory, including kernel and userspace memory. Accidental
> -- 
> 2.7.4
> 
> 
> -- 
> Kees Cook
> Pixel Security

  parent reply	other threads:[~2017-12-04 15:56 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-01 20:10 [kernel-hardening] [PATCH] Kconfig: Make STRICT_DEVMEM default-y on x86 and arm64 Kees Cook
2017-12-01 20:10 ` Kees Cook
2017-12-01 20:46 ` [kernel-hardening] " Laura Abbott
2017-12-01 20:46   ` Laura Abbott
2017-12-04 15:56 ` Will Deacon [this message]
2017-12-04 15:56   ` Will Deacon
2017-12-04 18:19   ` [kernel-hardening] " Kees Cook
2017-12-04 18:19     ` Kees Cook
2017-12-12 10:56 ` [tip:core/debug] " tip-bot for Kees Cook
2017-12-19 13:33 ` [kernel-hardening] [PATCH] " Ard Biesheuvel

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