From: Michael Tremer <michael.tremer@ipfire.org>
To: development@lists.ipfire.org
Subject: Re: [PATCH] linux: Randomize layout of sensitive kernel structures
Date: Wed, 03 Aug 2022 11:51:29 +0100 [thread overview]
Message-ID: <48CB1D4E-86BE-4422-9A50-86BD56D6A56E@ipfire.org> (raw)
In-Reply-To: <6f293556-db9a-086e-1b2d-5e7d10eee48b@ipfire.org>
[-- Attachment #1: Type: text/plain, Size: 8186 bytes --]
Acked-by: Michael Tremer <michael.tremer(a)ipfire.org>
> On 1 Aug 2022, at 18:18, Peter Müller <peter.mueller(a)ipfire.org> wrote:
>
> To quote from the kernel documentation:
>
>> If you say Y here, the layouts of structures that are entirely
>> function pointers (and have not been manually annotated with
>> __no_randomize_layout), or structures that have been explicitly
>> marked with __randomize_layout, will be randomized at compile-time.
>> This can introduce the requirement of an additional information
>> exposure vulnerability for exploits targeting these structure
>> types.
>>
>> Enabling this feature will introduce some performance impact,
>> slightly increase memory usage, and prevent the use of forensic
>> tools like Volatility against the system (unless the kernel
>> source tree isn't cleaned after kernel installation).
>>
>> The seed used for compilation is located at
>> scripts/gcc-plgins/randomize_layout_seed.h. It remains after
>> a make clean to allow for external modules to be compiled with
>> the existing seed and will be removed by a make mrproper or
>> make distclean.
>>
>> Note that the implementation requires gcc 4.7 or newer.
>
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> ---
> config/kernel/kernel.config.x86_64-ipfire | 3 ++-
> config/rootfiles/common/aarch64/linux | 5 +++++
> config/rootfiles/common/armv6l/linux | 5 +++++
> config/rootfiles/common/x86_64/linux | 5 +++++
> 4 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/config/kernel/kernel.config.x86_64-ipfire b/config/kernel/kernel.config.x86_64-ipfire
> index 40975b5fc..c8e7ada01 100644
> --- a/config/kernel/kernel.config.x86_64-ipfire
> +++ b/config/kernel/kernel.config.x86_64-ipfire
> @@ -793,7 +793,8 @@ CONFIG_HAVE_GCC_PLUGINS=y
> CONFIG_GCC_PLUGINS=y
> # CONFIG_GCC_PLUGIN_CYC_COMPLEXITY is not set
> CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
> -# CONFIG_GCC_PLUGIN_RANDSTRUCT is not set
> +CONFIG_GCC_PLUGIN_RANDSTRUCT=y
> +CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE=y
> # end of General architecture-dependent options
>
> CONFIG_RT_MUTEXES=y
> diff --git a/config/rootfiles/common/aarch64/linux b/config/rootfiles/common/aarch64/linux
> index dbd6e8f2f..b3a642e56 100644
> --- a/config/rootfiles/common/aarch64/linux
> +++ b/config/rootfiles/common/aarch64/linux
> @@ -7646,6 +7646,8 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/include/config/GARP
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGINS
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_LATENT_ENTROPY
> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT
> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
> #lib/modules/KVER-ipfire/build/include/config/GCC_VERSION
> @@ -11684,6 +11686,7 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/include/generated/autoconf.h
> #lib/modules/KVER-ipfire/build/include/generated/bounds.h
> #lib/modules/KVER-ipfire/build/include/generated/compile.h
> +#lib/modules/KVER-ipfire/build/include/generated/randomize_layout_hash.h
> #lib/modules/KVER-ipfire/build/include/generated/timeconst.h
> #lib/modules/KVER-ipfire/build/include/generated/uapi
> #lib/modules/KVER-ipfire/build/include/generated/uapi/linux
> @@ -17129,6 +17132,8 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.so
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.c
> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.so
> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_seed.h
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/sancov_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/stackleak_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/structleak_plugin.c
> diff --git a/config/rootfiles/common/armv6l/linux b/config/rootfiles/common/armv6l/linux
> index 79e4facfe..c3411fe8d 100644
> --- a/config/rootfiles/common/armv6l/linux
> +++ b/config/rootfiles/common/armv6l/linux
> @@ -8071,6 +8071,8 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGINS
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_ARM_SSP_PER_TASK
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_LATENT_ENTROPY
> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT
> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
> #lib/modules/KVER-ipfire/build/include/config/GCC_VERSION
> @@ -12134,6 +12136,7 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/include/generated/autoconf.h
> #lib/modules/KVER-ipfire/build/include/generated/bounds.h
> #lib/modules/KVER-ipfire/build/include/generated/compile.h
> +#lib/modules/KVER-ipfire/build/include/generated/randomize_layout_hash.h
> #lib/modules/KVER-ipfire/build/include/generated/timeconst.h
> #lib/modules/KVER-ipfire/build/include/generated/uapi
> #lib/modules/KVER-ipfire/build/include/generated/uapi/linux
> @@ -17579,6 +17582,8 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.so
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.c
> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.so
> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_seed.h
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/sancov_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/stackleak_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/structleak_plugin.c
> diff --git a/config/rootfiles/common/x86_64/linux b/config/rootfiles/common/x86_64/linux
> index b25f85a3a..1b78fe8c5 100644
> --- a/config/rootfiles/common/x86_64/linux
> +++ b/config/rootfiles/common/x86_64/linux
> @@ -7624,6 +7624,8 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/include/config/GARP
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGINS
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_LATENT_ENTROPY
> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT
> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK
> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
> #lib/modules/KVER-ipfire/build/include/config/GCC_VERSION
> @@ -12128,6 +12130,7 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/include/generated/autoconf.h
> #lib/modules/KVER-ipfire/build/include/generated/bounds.h
> #lib/modules/KVER-ipfire/build/include/generated/compile.h
> +#lib/modules/KVER-ipfire/build/include/generated/randomize_layout_hash.h
> #lib/modules/KVER-ipfire/build/include/generated/timeconst.h
> #lib/modules/KVER-ipfire/build/include/generated/uapi
> #lib/modules/KVER-ipfire/build/include/generated/uapi/linux
> @@ -17567,6 +17570,8 @@ etc/modprobe.d/ipv6.conf
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.so
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.c
> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.so
> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_seed.h
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/sancov_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/stackleak_plugin.c
> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/structleak_plugin.c
> --
> 2.35.3
prev parent reply other threads:[~2022-08-03 10:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-01 17:18 Peter Müller
2022-08-01 20:18 ` Michael Tremer
2022-08-02 15:13 ` Peter Müller
2022-08-03 8:30 ` Michael Tremer
2022-08-03 9:59 ` Peter Müller
2022-08-03 10:28 ` Michael Tremer
2022-08-03 10:51 ` Michael Tremer [this message]
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