tty: nozomi: Fix the error handling path of 'nozomi_card_init()'

[ Upstream commit 6ae7d0f ]

The error handling path is broken and we may un-register things that have
never been registered.

Update the loops index accordingly.

Fixes: 9842c38 ("kfifo: fix warn_unused_result")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/e28c2e92c7475da25b03d022ea2d6dcf1ba807a2.1621968629.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/tty/nozomi.c

@@ -1391,7 +1391,7 @@ static int nozomi_card_init(struct pci_dev *pdev,
 			NOZOMI_NAME, dc);
 	if (unlikely(ret)) {
 		dev_err(&pdev->dev, "can't request irq %d\n", pdev->irq);
-		goto err_free_kfifo;
+		goto err_free_all_kfifo;
 	}
 
 	DBG1("base_addr: %p", dc->base_addr);
@@ -1429,13 +1429,15 @@ static int nozomi_card_init(struct pci_dev *pdev,
 	return 0;
 
 err_free_tty:
-	for (i = 0; i < MAX_PORT; ++i) {
+	for (i--; i >= 0; i--) {
 		tty_unregister_device(ntty_driver, dc->index_start + i);
 		tty_port_destroy(&dc->port[i].port);
 	}
 	free_irq(pdev->irq, dc);
+err_free_all_kfifo:
+	i = MAX_PORT;
 err_free_kfifo:
-	for (i = 0; i < MAX_PORT; i++)
+	for (i--; i >= PORT_MDM; i--)
 		kfifo_free(&dc->port[i].fifo_ul);
 err_free_sbuf:
 	kfree(dc->send_buf);