[PATCH 4.14 140/315] tty: nozomi: Fix the error handling path of nozomi_card_init()

[Greg Kroah-Hartman]

From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

[ Upstream commit 6ae7d0f5a92b9619f6e3c307ce56b2cefff3f0e9 ]

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

Update the loops index accordingly.

Fixes: 9842c38e9176 ("kfifo: fix warn_unused_result")
Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Link: https://lore.kernel.org/r/e28c2e92c7475da25b03d022ea2d6dcf1ba807a2.1621968629.git.christophe.jaillet@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/nozomi.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index d19acddc3cf3..0c424624a00c 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -1416,7 +1416,7 @@ 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);
@@ -1454,13 +1454,15 @@ 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);
-- 
2.30.2