diff --git a/drivers/platform/chrome/cros_ec_chardev.c b/drivers/platform/chrome/cros_ec_chardev.c
index fd33de546aee..0de7c255254e 100644
--- a/drivers/platform/chrome/cros_ec_chardev.c
+++ b/drivers/platform/chrome/cros_ec_chardev.c
@@ -327,6 +327,9 @@ static long cros_ec_chardev_ioctl_readmem(struct cros_ec_dev *ec,
 	if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
 		return -EFAULT;
 
+	if (s_mem.bytes > sizeof(s_mem.buffer))
+		return -EINVAL;
+
 	num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
 				  s_mem.buffer);
 	if (num <= 0)