From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Date: Wed, 10 Jan 2018 18:03:06 -0800 Message-Id: <1515636190-24061-35-git-send-email-keescook@chromium.org> In-Reply-To: <1515636190-24061-1-git-send-email-keescook@chromium.org> References: <1515636190-24061-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH 34/38] arm: Implement thread_struct whitelist for hardened usercopy To: linux-kernel@vger.kernel.org Cc: Kees Cook , Russell King , Ingo Molnar , Christian Borntraeger , "Peter Zijlstra (Intel)" , linux-arm-kernel@lists.infradead.org, Linus Torvalds , David Windsor , Alexander Viro , Andrew Morton , Andy Lutomirski , Christoph Hellwig , Christoph Lameter , "David S. Miller" , Laura Abbott , Mark Rutland , "Martin K. Petersen" , Paolo Bonzini , Christoffer Dall , Dave Kleikamp , Jan Kara , Luis de Bethencourt , Marc Zyngier , Rik van Riel , Matthew Garrett , linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com List-ID: ARM does not carry FPU state in the thread structure, so it can declare no usercopy whitelist at all. Cc: Russell King Cc: Ingo Molnar Cc: Christian Borntraeger Cc: "Peter Zijlstra (Intel)" Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook --- arch/arm/Kconfig | 1 + arch/arm/include/asm/processor.h | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 51c8df561077..3ea00d65f35d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -50,6 +50,7 @@ config ARM select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) + select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK select HAVE_ARM_SMCCC if CPU_V7 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32 diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index 338cbe0a18ef..01a41be58d43 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -45,6 +45,13 @@ struct thread_struct { struct debug_info debug; }; +/* Nothing needs to be usercopy-whitelisted from thread_struct. */ +static inline void arch_thread_struct_whitelist(unsigned long *offset, + unsigned long *size) +{ + *offset = *size = 0; +} + #define INIT_THREAD { } #define start_thread(regs,pc,sp) \ -- 2.7.4