[PATCH 31/36] arm: Implement thread_struct whitelist for hardened usercopy
From: Kees Cook <hidden>
Date: 2018-01-09 20:56:00
Also in:
linux-arch, linux-arm-kernel, linux-fsdevel, linux-mm, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
ARM does not carry FPU state in the thread structure, so it can declare no usercopy whitelist at all. Cc: Russell King <linux@armlinux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christian Borntraeger <redacted> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook <redacted> --- 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) \
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2.7.4