arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user


From: Will Deacon <will.deacon@arm.com>

commit f71c2ffcb20dd8626880747557014bb9a61eb90e upstream.

Like we've done for get_user and put_user, ensure that user pointers
are masked before invoking the underlying __arch_{clear,copy_*}_user
operations.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[v4.9: fixup for v4.9-style uaccess primitives]
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 0d4330c..1d047d6 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -313,21 +313,20 @@
 
 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);
+extern unsigned long __must_check __arch_copy_in_user(void __user *to, const void __user *from, unsigned long n);
 
 static inline unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n)
 {
 	kasan_check_write(to, n);
 	check_object_size(to, n, false);
-	return __arch_copy_from_user(to, from, n);
+	return __arch_copy_from_user(to, __uaccess_mask_ptr(from), n);
 }
 
 static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
 	kasan_check_read(from, n);
 	check_object_size(from, n, true);
-	return __arch_copy_to_user(to, from, n);
+	return __arch_copy_to_user(__uaccess_mask_ptr(to), from, n);
 }
 
 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
@@ -355,22 +354,25 @@
 	return n;
 }
 
-static inline unsigned long __must_check copy_in_user(void __user *to, const void __user *from, unsigned long n)
+static inline unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
 	if (access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n))
-		n = __copy_in_user(to, from, n);
+		n = __arch_copy_in_user(__uaccess_mask_ptr(to), __uaccess_mask_ptr(from), n);
 	return n;
 }
+#define copy_in_user __copy_in_user
 
 #define __copy_to_user_inatomic __copy_to_user
 #define __copy_from_user_inatomic __copy_from_user
 
-static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
+extern unsigned long __must_check __arch_clear_user(void __user *to, unsigned long n);
+static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n)
 {
 	if (access_ok(VERIFY_WRITE, to, n))
-		n = __clear_user(__uaccess_mask_ptr(to), n);
+		n = __arch_clear_user(__uaccess_mask_ptr(to), n);
 	return n;
 }
+#define clear_user	__clear_user
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);