1 files changed, 13 insertions, 7 deletions

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 5dea1fb6979c..6df9b0749671 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -231,14 +231,18 @@ extern int __put_user_bad(void) __attribute__((noreturn));
         might_fault();                                          \
         access_ok(VERIFY_READ, __p, sizeof(*ptr)) ?             \
                 __get_user((x), (__typeof__(*(ptr)) *)__p) :    \
-                -EFAULT;                                        \
+                ((x) = (__typeof__(*(ptr)))0,-EFAULT);          \
 })
 
 #ifndef __get_user_fn
 static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
 {
-        size = __copy_from_user(x, ptr, size);
-        return size ? -EFAULT : size;
+        size_t n = __copy_from_user(x, ptr, size);
+        if (unlikely(n)) {
+                memset(x + (size - n), 0, n);
+                return -EFAULT;
+        }
+        return 0;
 }
 
 #define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
@@ -258,11 +262,13 @@ extern int __get_user_bad(void) __attribute__((noreturn));
 static inline long copy_from_user(void *to,
                 const void __user * from, unsigned long n)
 {
+        unsigned long res = n;
         might_fault();
-        if (access_ok(VERIFY_READ, from, n))
-                return __copy_from_user(to, from, n);
-        else
-                return n;
+        if (likely(access_ok(VERIFY_READ, from, n)))
+                res = __copy_from_user(to, from, n);
+        if (unlikely(res))
+                memset(to + (n - res), 0, res);
+        return res;
 }
 
 static inline long copy_to_user(void __user *to,