arm: Implement thread_struct whitelist for hardened usercopy (08626a60) · Commits · 戴 / test

While ARM32 carries FPU state in the thread structure that is saved and restored during signal handling, it doesn't need to declare a usercopy whitelist, since existing accessors are all either using a bounce buffer (for which whitelisting isn't checking the slab), are statically sized (which will bypass the hardened usercopy check), or both. Cc: Russell King <linux@armlinux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by:

Kees Cook <keescook@chromium.org>

arch/arm/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/arm/include/asm/processor.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,16 @@ struct thread_struct {
		struct debug_info debug;
		};

		/*
		* Everything usercopied to/from thread_struct is statically-sized, so
		* no hardened usercopy whitelist is needed.
		*/
		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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