ia64: copy_from_user() should zero the destination on access_ok() failure
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 19 Aug 2016 01:31:41 +0000 (21:31 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Tue, 13 Sep 2016 21:49:40 +0000 (17:49 -0400)
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
arch/ia64/include/asm/uaccess.h

index 465c709..6c2d2c8 100644 (file)
@@ -272,20 +272,17 @@ __copy_from_user (void *to, const void __user *from, unsigned long count)
        __cu_len;                                                                       \
 })
 
        __cu_len;                                                                       \
 })
 
-#define copy_from_user(to, from, n)                                                    \
-({                                                                                     \
-       void *__cu_to = (to);                                                           \
-       const void __user *__cu_from = (from);                                          \
-       long __cu_len = (n);                                                            \
-                                                                                       \
-       __chk_user_ptr(__cu_from);                                                      \
-       if (__access_ok(__cu_from, __cu_len, get_fs())) {                               \
-               if (!__builtin_constant_p(n))                                           \
-                       check_object_size(__cu_to, __cu_len, false);                    \
-               __cu_len = __copy_user((__force void __user *) __cu_to, __cu_from, __cu_len);   \
-       }                                                                               \
-       __cu_len;                                                                       \
-})
+static inline unsigned long
+copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+       if (!__builtin_constant_p(n))
+               check_object_size(to, n, false);
+       if (likely(__access_ok(from, n, get_fs())))
+               n = __copy_user((__force void __user *) to, from, n);
+       else
+               memset(to, 0, n);
+       return n;
+}
 
 #define __copy_in_user(to, from, size) __copy_user((to), (from), (size))
 
 
 #define __copy_in_user(to, from, size) __copy_user((to), (from), (size))