diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index b7c816f39404..6dd63981787a 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -148,6 +148,15 @@ static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
 				cmd);
 			goto out;
 		}
+	} else {
+		unsigned int inr = _IOC_NR(cmd);
+
+		if (inr == AUTOFS_DEV_IOCTL_OPENMOUNT_CMD ||
+		    inr == AUTOFS_DEV_IOCTL_REQUESTER_CMD ||
+		    inr == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) {
+			err = -EINVAL;
+			goto out;
+		}
 	}
 
 	err = 0;
@@ -284,7 +293,8 @@ static int autofs_dev_ioctl_openmount(struct file *fp,
 	dev_t devid;
 	int err, fd;
 
-	/* param->path has already been checked */
+	/* param->path has been checked in validate_dev_ioctl() */
+
 	if (!param->openmount.devid)
 		return -EINVAL;
 
@@ -446,10 +456,7 @@ static int autofs_dev_ioctl_requester(struct file *fp,
 	dev_t devid;
 	int err = -ENOENT;
 
-	if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
-		err = -EINVAL;
-		goto out;
-	}
+	/* param->path has been checked in validate_dev_ioctl() */
 
 	devid = sbi->sb->s_dev;
 
@@ -534,10 +541,7 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp,
 	unsigned int devid, magic;
 	int err = -ENOENT;
 
-	if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
-		err = -EINVAL;
-		goto out;
-	}
+	/* param->path has been checked in validate_dev_ioctl() */
 
 	name = param->path;
 	type = param->ismountpoint.in.type;