sh: fix copy_from_user()

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/sh/include/asm/uaccess.h b/arch/sh/include/asm/uaccess.h
index a49635c51266..92ade79ac427 100644
--- a/arch/sh/include/asm/uaccess.h
+++ b/arch/sh/include/asm/uaccess.h
@@ -151,7 +151,10 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
         __kernel_size_t __copy_size = (__kernel_size_t) n;
 
         if (__copy_size && __access_ok(__copy_from, __copy_size))
-                return __copy_user(to, from, __copy_size);
+                __copy_size = __copy_user(to, from, __copy_size);
+
+        if (unlikely(__copy_size))
+                memset(to + (n - __copy_size), 0, __copy_size);
 
         return __copy_size;
 }