[PATCH v2 05/11] arm64/uaccess: Enable hardened usercopy
From: Kees Cook <hidden>
Date: 2016-07-13 21:57:21
Also in:
linux-arm-kernel, linux-mm, linuxppc-dev, lkml, sparclinux
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Enables CONFIG_HARDENED_USERCOPY checks on arm64. As done by KASAN in -next, renames the low-level functions to __arch_copy_*_user() so a static inline can do additional work before the copy. Signed-off-by: Kees Cook <redacted> --- arch/arm64/Kconfig | 2 ++ arch/arm64/include/asm/uaccess.h | 16 ++++++++++++++-- arch/arm64/kernel/arm64ksyms.c | 4 ++-- arch/arm64/lib/copy_from_user.S | 4 ++-- arch/arm64/lib/copy_to_user.S | 4 ++-- 5 files changed, 22 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5a0a691d4220..b771cd97f74b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -51,10 +51,12 @@ config ARM64 select HAVE_ALIGNED_STRUCT_PAGE if SLUB select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_BITREVERSE + select HAVE_ARCH_HARDENED_USERCOPY select HAVE_ARCH_HUGE_VMAP select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48) select HAVE_ARCH_KGDB + select HAVE_ARCH_LINEAR_KERNEL_MAPPING select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT select HAVE_ARCH_SECCOMP_FILTER
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 9e397a542756..5d0dacdb695b 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h@@ -256,11 +256,23 @@ do { \ -EFAULT; \ }) -extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); -extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); +extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n); +extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n); extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n); extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); +static inline unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n) +{ + check_object_size(to, n, false); + return __arch_copy_from_user(to, from, n); +} + +static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n) +{ + check_object_size(from, n, true); + return __arch_copy_to_user(to, from, n); +} + static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) { if (access_ok(VERIFY_READ, from, n))
diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index 678f30b05a45..2dc44406a7ad 100644
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c@@ -34,8 +34,8 @@ EXPORT_SYMBOL(copy_page); EXPORT_SYMBOL(clear_page); /* user mem (segment) */ -EXPORT_SYMBOL(__copy_from_user); -EXPORT_SYMBOL(__copy_to_user); +EXPORT_SYMBOL(__arch_copy_from_user); +EXPORT_SYMBOL(__arch_copy_to_user); EXPORT_SYMBOL(__clear_user); EXPORT_SYMBOL(__copy_in_user);
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 17e8306dca29..0b90497d4424 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S@@ -66,7 +66,7 @@ .endm end .req x5 -ENTRY(__copy_from_user) +ENTRY(__arch_copy_from_user) ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) add end, x0, x2
@@ -75,7 +75,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) mov x0, #0 // Nothing to copy ret -ENDPROC(__copy_from_user) +ENDPROC(__arch_copy_from_user) .section .fixup,"ax" .align 2
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 21faae60f988..7a7efe255034 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S@@ -65,7 +65,7 @@ .endm end .req x5 -ENTRY(__copy_to_user) +ENTRY(__arch_copy_to_user) ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) add end, x0, x2
@@ -74,7 +74,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) mov x0, #0 ret -ENDPROC(__copy_to_user) +ENDPROC(__arch_copy_to_user) .section .fixup,"ax" .align 2
--
2.7.4
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