From: Diana Madalina Craciun <diana.craciun@nxp.com>
To: Jason Yan <yanaijie@huawei.com>,
"mpe@ellerman.id.au" <mpe@ellerman.id.au>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"christophe.leroy@c-s.fr" <christophe.leroy@c-s.fr>,
"benh@kernel.crashing.org" <benh@kernel.crashing.org>,
"paulus@samba.org" <paulus@samba.org>,
"npiggin@gmail.com" <npiggin@gmail.com>,
"keescook@chromium.org" <keescook@chromium.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"wangkefeng.wang@huawei.com" <wangkefeng.wang@huawei.com>,
"yebin10@huawei.com" <yebin10@huawei.com>,
"thunder.leizhen@huawei.com" <thunder.leizhen@huawei.com>,
"jingxiangfeng@huawei.com" <jingxiangfeng@huawei.com>,
"fanchengyang@huawei.com" <fanchengyang@huawei.com>
Subject: Re: [RFC PATCH 00/10] implement KASLR for powerpc/fsl_booke/32
Date: Mon, 29 Jul 2019 14:30:15 +0000 [thread overview]
Message-ID: <VI1PR0401MB24633E9C5475F8D50536C46FFFDD0@VI1PR0401MB2463.eurprd04.prod.outlook.com> (raw)
In-Reply-To: 20190717080621.40424-1-yanaijie@huawei.com
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
On 7/17/2019 10:49 AM, Jason Yan wrote:
> This series implements KASLR for powerpc/fsl_booke/32, as a security
> feature that deters exploit attempts relying on knowledge of the location
> of kernel internals.
>
> Since CONFIG_RELOCATABLE has already supported, what we need to do is
> map or copy kernel to a proper place and relocate. Freescale Book-E
> parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
> entries are not suitable to map the kernel directly in a randomized
> region, so we chose to copy the kernel to a proper place and restart to
> relocate.
>
> Entropy is derived from the banner and timer base, which will change every
> build and boot. This not so much safe so additionally the bootloader may
> pass entropy via the /chosen/kaslr-seed node in device tree.
>
> We will use the first 512M of the low memory to randomize the kernel
> image. The memory will be split in 64M zones. We will use the lower 8
> bit of the entropy to decide the index of the 64M zone. Then we chose a
> 16K aligned offset inside the 64M zone to put the kernel in.
>
> KERNELBASE
>
> |--> 64M <--|
> | |
> +---------------+ +----------------+---------------+
> | |....| |kernel| | |
> +---------------+ +----------------+---------------+
> | |
> |-----> offset <-----|
>
> kimage_vaddr
>
> We also check if we will overlap with some areas like the dtb area, the
> initrd area or the crashkernel area. If we cannot find a proper area,
> kaslr will be disabled and boot from the original kernel.
>
> Jason Yan (10):
> powerpc: unify definition of M_IF_NEEDED
> powerpc: move memstart_addr and kernstart_addr to init-common.c
> powerpc: introduce kimage_vaddr to store the kernel base
> powerpc/fsl_booke/32: introduce create_tlb_entry() helper
> powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
> powerpc/fsl_booke/32: implement KASLR infrastructure
> powerpc/fsl_booke/32: randomize the kernel image offset
> powerpc/fsl_booke/kaslr: clear the original kernel if randomized
> powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter
> powerpc/fsl_booke/kaslr: dump out kernel offset information on panic
>
> arch/powerpc/Kconfig | 11 +
> arch/powerpc/include/asm/nohash/mmu-book3e.h | 10 +
> arch/powerpc/include/asm/page.h | 7 +
> arch/powerpc/kernel/Makefile | 1 +
> arch/powerpc/kernel/early_32.c | 2 +-
> arch/powerpc/kernel/exceptions-64e.S | 10 -
> arch/powerpc/kernel/fsl_booke_entry_mapping.S | 23 +-
> arch/powerpc/kernel/head_fsl_booke.S | 61 ++-
> arch/powerpc/kernel/kaslr_booke.c | 439 ++++++++++++++++++
> arch/powerpc/kernel/machine_kexec.c | 1 +
> arch/powerpc/kernel/misc_64.S | 5 -
> arch/powerpc/kernel/setup-common.c | 23 +
> arch/powerpc/mm/init-common.c | 7 +
> arch/powerpc/mm/init_32.c | 5 -
> arch/powerpc/mm/init_64.c | 5 -
> arch/powerpc/mm/mmu_decl.h | 10 +
> arch/powerpc/mm/nohash/fsl_booke.c | 8 +-
> 17 files changed, 580 insertions(+), 48 deletions(-)
> create mode 100644 arch/powerpc/kernel/kaslr_booke.c
>
prev parent reply other threads:[~2019-07-29 14:38 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-17 8:06 [RFC PATCH 00/10] implement KASLR for powerpc/fsl_booke/32 Jason Yan
2019-07-17 8:06 ` [RFC PATCH 01/10] powerpc: unify definition of M_IF_NEEDED Jason Yan
2019-07-29 10:59 ` Christophe Leroy
2019-07-17 8:06 ` [RFC PATCH 02/10] powerpc: move memstart_addr and kernstart_addr to init-common.c Jason Yan
2019-07-29 11:00 ` Christophe Leroy
2019-07-29 14:31 ` Christoph Hellwig
2019-07-30 0:47 ` Jason Yan
2019-07-17 8:06 ` [RFC PATCH 03/10] powerpc: introduce kimage_vaddr to store the kernel base Jason Yan
2019-07-29 11:00 ` Christophe Leroy
2019-07-29 14:32 ` Christoph Hellwig
2019-07-17 8:06 ` [RFC PATCH 04/10] powerpc/fsl_booke/32: introduce create_tlb_entry() helper Jason Yan
2019-07-29 11:05 ` Christophe Leroy
2019-07-29 13:26 ` Jason Yan
2019-07-17 8:06 ` [RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper Jason Yan
2019-07-29 11:08 ` Christophe Leroy
2019-07-29 13:35 ` Jason Yan
2019-07-17 8:06 ` [RFC PATCH 06/10] powerpc/fsl_booke/32: implement KASLR infrastructure Jason Yan
2019-07-29 11:16 ` Christophe Leroy
2019-07-17 8:06 ` [RFC PATCH 07/10] powerpc/fsl_booke/32: randomize the kernel image offset Jason Yan
2019-07-29 11:33 ` Christophe Leroy
2019-07-29 13:53 ` Jason Yan
2019-07-17 8:06 ` [RFC PATCH 08/10] powerpc/fsl_booke/kaslr: clear the original kernel if randomized Jason Yan
2019-07-29 11:19 ` Christophe Leroy
2019-07-29 13:43 ` Jason Yan
2019-07-17 8:06 ` [RFC PATCH 09/10] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter Jason Yan
2019-07-29 11:38 ` Christophe Leroy
2019-07-29 14:04 ` Jason Yan
2019-07-17 8:06 ` [RFC PATCH 10/10] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic Jason Yan
2019-07-29 11:43 ` Christophe Leroy
2019-07-29 14:08 ` Jason Yan
2019-07-25 7:16 ` [RFC PATCH 00/10] implement KASLR for powerpc/fsl_booke/32 Jason Yan
2019-07-25 19:58 ` Kees Cook
2019-07-26 7:20 ` Jason Yan
2019-07-26 16:15 ` Kees Cook
2019-07-26 7:04 ` Diana Madalina Craciun
2019-07-26 7:26 ` Jason Yan
2019-07-29 14:30 ` Diana Madalina Craciun [this message]
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