2022-11-21 11:03:11

by Zhang Changzhong

[permalink] [raw]

Subject: [PATCH] can: sja1000: plx_pci: fix error handling path in plx_pci_add_card()

---

If pci_iomap() or register_sja1000dev() fails, netdev will not be
registered, but plx_pci_del_card() still deregisters the netdev.

To avoid this, let's free the netdev and clear card->net_dev[i] before
calling plx_pci_del_card(). In addition, add the missing pci_iounmap()
when the channel does not exist.

Compile tested only.

Fixes: 951f2f960e5b ("drivers/net/can/sja1000/plx_pci.c: eliminate double free")
Fixes: 24c4a3b29255 ("can: add support for CAN interface cards based on the PLX90xx PCI bridge")
Signed-off-by: Zhang Changzhong <[email protected]>
---
drivers/net/can/sja1000/plx_pci.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/net/can/sja1000/plx_pci.c b/drivers/net/can/sja1000/plx_pci.c
index 5de1ebb..1158f5a 100644
--- a/drivers/net/can/sja1000/plx_pci.c
+++ b/drivers/net/can/sja1000/plx_pci.c
@@ -678,6 +678,8 @@ static int plx_pci_add_card(struct pci_dev *pdev,
if (!addr) {
err = -ENOMEM;
dev_err(&pdev->dev, "Failed to remap BAR%d\n", cm->bar);
+ free_sja1000dev(dev);
+ card->net_dev[i] = NULL;
goto failure_cleanup;
}

@@ -699,6 +701,9 @@ static int plx_pci_add_card(struct pci_dev *pdev,
if (err) {
dev_err(&pdev->dev, "Registering device failed "
"(err=%d)\n", err);
+ pci_iounmap(pdev, priv->reg_base);
+ free_sja1000dev(dev);
+ card->net_dev[i] = NULL;
goto failure_cleanup;
}

@@ -710,6 +715,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
} else {
dev_err(&pdev->dev, "Channel #%d not detected\n",
i + 1);
+ pci_iounmap(pdev, priv->reg_base);
free_sja1000dev(dev);
card->net_dev[i] = NULL;
}
--
2.9.5

2022-11-24 14:56:27

by Marc Kleine-Budde

[permalink] [raw]

Subject: Re: [PATCH] can: sja1000: plx_pci: fix error handling path in plx_pci_add_card()

---

On 21.11.2022 19:10:30, Zhang Changzhong wrote:
> If pci_iomap() or register_sja1000dev() fails, netdev will not be
> registered, but plx_pci_del_card() still deregisters the netdev.
>
> To avoid this, let's free the netdev and clear card->net_dev[i] before
> calling plx_pci_del_card(). In addition, add the missing pci_iounmap()
> when the channel does not exist.
>
> Compile tested only.
>
> Fixes: 951f2f960e5b ("drivers/net/can/sja1000/plx_pci.c: eliminate double free")
> Fixes: 24c4a3b29255 ("can: add support for CAN interface cards based on the PLX90xx PCI bridge")
> Signed-off-by: Zhang Changzhong <[email protected]>
> ---
> drivers/net/can/sja1000/plx_pci.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/can/sja1000/plx_pci.c b/drivers/net/can/sja1000/plx_pci.c
> index 5de1ebb..1158f5a 100644
> --- a/drivers/net/can/sja1000/plx_pci.c
> +++ b/drivers/net/can/sja1000/plx_pci.c
> @@ -678,6 +678,8 @@ static int plx_pci_add_card(struct pci_dev *pdev,
> if (!addr) {
> err = -ENOMEM;
> dev_err(&pdev->dev, "Failed to remap BAR%d\n", cm->bar);
> + free_sja1000dev(dev);
> + card->net_dev[i] = NULL;
> goto failure_cleanup;
> }
>
> @@ -699,6 +701,9 @@ static int plx_pci_add_card(struct pci_dev *pdev,
> if (err) {
> dev_err(&pdev->dev, "Registering device failed "
> "(err=%d)\n", err);
> + pci_iounmap(pdev, priv->reg_base);
> + free_sja1000dev(dev);
> + card->net_dev[i] = NULL;
> goto failure_cleanup;
> }
>
> @@ -710,6 +715,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
> } else {
> dev_err(&pdev->dev, "Channel #%d not detected\n",
> i + 1);
> + pci_iounmap(pdev, priv->reg_base);
> free_sja1000dev(dev);
> card->net_dev[i] = NULL;

There's quite some cleanup code doubling. Can you introduce a goto style
cleanup?

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

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