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Commit 9e8084d3 authored by Kees Cook's avatar Kees Cook
Browse files

arm64: Implement thread_struct whitelist for hardened usercopy 



While ARM64 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: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: zijun_hu <zijun_hu@htc.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent f7d83c1c

arch/arm64/Kconfig

+1 −0
Original line number Original line Diff line number Diff line
@@ -90,6 +90,7 @@ config ARM64 
	select HAVE_ARCH_MMAP_RND_BITS

	select HAVE_ARCH_MMAP_RND_BITS

	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT

	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_THREAD_STRUCT_WHITELIST

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRANSPARENT_HUGEPAGE

	select HAVE_ARCH_TRANSPARENT_HUGEPAGE

	select HAVE_ARCH_VMAP_STACK

	select HAVE_ARCH_VMAP_STACK

arch/arm64/include/asm/processor.h

+10 −0
Original line number Original line Diff line number Diff line
@@ -113,6 +113,16 @@ struct thread_struct { 
	struct debug_info	debug;		/* debugging */

	struct debug_info	debug;		/* debugging */

};

};





/*

 * 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;

}



#ifdef CONFIG_COMPAT

#ifdef CONFIG_COMPAT

#define task_user_tls(t)						\

#define task_user_tls(t)						\

({									\

({									\