1 files changed, 7 insertions, 8 deletions
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index c905e89e19fe..1f33b3d1fd68 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -69,21 +69,20 @@ EXPORT_SYMBOL(copy_in_user);
  * it is not necessary to optimize tail handling.
  */
 __visible unsigned long
-copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest)
+copy_user_handle_tail(char *to, char *from, unsigned len)
 {
-	char c;
-	unsigned zero_len;
-
 	for (; len; --len, to++) {
+		char c;
+
 		if (__get_user_nocheck(c, from++, sizeof(char)))
 			break;
 		if (__put_user_nocheck(c, to, sizeof(char)))
 			break;
 	}
-
-	for (c = 0, zero_len = len; zerorest && zero_len; --zero_len)
-		if (__put_user_nocheck(c, to++, sizeof(char)))
-			break;
 	clac();
+
+	/* If the destination is a kernel buffer, we always clear the end */
+	if ((unsigned long)to >= TASK_SIZE_MAX)
+		memset(to, 0, len);
 	return len;
 }