diff --git a/drivers/net/wireless/rt2x00/rt2x00debug.c b/drivers/net/wireless/rt2x00/rt2x00debug.c
index 74f0d679883e2d07e021657351c66ca2e92e24df..daf7f950a28f1f7d38abfbebf3728adb5e0523ff 100644
--- a/drivers/net/wireless/rt2x00/rt2x00debug.c
+++ b/drivers/net/wireless/rt2x00/rt2x00debug.c
@@ -480,6 +480,9 @@ static ssize_t rt2x00debug_write_##__name(struct file *file,	\
 	if (index >= debug->__name.word_count)			\
 		return -EINVAL;					\
 								\
+	if (length > sizeof(line))				\
+		return -EINVAL;					\
+								\
 	if (copy_from_user(line, buf, length))			\
 		return -EFAULT;					\
 								\