[PATCH 4.7 171/184] mips: copy_from_user() must zero the destination on access_ok() failure

[Greg Kroah-Hartman]

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

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

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit e69d700535ac43a18032b3c399c69bf4639e89a2 upstream.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/mips/include/asm/uaccess.h |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -14,6 +14,7 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/thread_info.h>
+#include <linux/string.h>
 #include <asm/asm-eva.h>
 
 /*
@@ -1170,6 +1171,8 @@ extern size_t __copy_in_user_eva(void *_
 			__cu_len = __invoke_copy_from_user(__cu_to,	\
 							   __cu_from,	\
 							   __cu_len);   \
+		} else {						\
+			memset(__cu_to, 0, __cu_len);			\
 		}							\
 	}								\
 	__cu_len;							\