diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index d41d7f018549..3266b4f65daa 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3497,6 +3497,9 @@ static int fd_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 	    ((cmd & 0x80) && !capable(CAP_SYS_ADMIN)))
 		return -EPERM;
 
+	if (WARN_ON(size < 0 || size > sizeof(inparam)))
+		return -EINVAL;
+
 	/* copyin */
 	CLEARSTRUCT(&inparam);
 	if (_IOC_DIR(cmd) & _IOC_WRITE)