4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@zeniv.linux.org.uk>

commit 917400cecb4b52b5cde5417348322bb9c8272fa6 upstream.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/sparc/include/asm/uaccess_32.h |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h

@@ -328,8 +328,10 @@ static inline unsigned long copy_from_us
 {
 	if (n && __access_ok((unsigned long) from, n))
 		return __copy_user((__force void __user *) to, from, n);
-	else
+	else {
+		memset(to, 0, n);
 		return n;
+	}
 }
 
 static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)