2023-10-05 00:08:26

by Justin Stitt

[permalink] [raw]
Subject: [PATCH] can: peak_pci: replace deprecated strncpy with strscpy

`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

NUL-padding is not required since card is already zero-initialized:
| card = kzalloc(sizeof(*card), GFP_KERNEL);

A suitable replacement is `strscpy` [2] due to the fact that it
guarantees NUL-termination on the destination buffer without
unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
---
Note: build-tested only.
---
drivers/net/can/sja1000/peak_pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c
index 84f34020aafb..da396d641e24 100644
--- a/drivers/net/can/sja1000/peak_pci.c
+++ b/drivers/net/can/sja1000/peak_pci.c
@@ -462,7 +462,7 @@ static int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
card->led_chip.owner = THIS_MODULE;
card->led_chip.dev.parent = &pdev->dev;
card->led_chip.algo_data = &card->i2c_bit;
- strncpy(card->led_chip.name, "peak_i2c",
+ strscpy(card->led_chip.name, "peak_i2c",
sizeof(card->led_chip.name));

card->i2c_bit = peak_pciec_i2c_bit_ops;

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231004-strncpy-drivers-net-can-sja1000-peak_pci-c-9c2e5e32be83

Best regards,
--
Justin Stitt <[email protected]>


2023-10-05 14:26:18

by Marc Kleine-Budde

[permalink] [raw]
Subject: Re: [PATCH] can: peak_pci: replace deprecated strncpy with strscpy

On 05.10.2023 00:05:35, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> NUL-padding is not required since card is already zero-initialized:
> | card = kzalloc(sizeof(*card), GFP_KERNEL);
>
> A suitable replacement is `strscpy` [2] due to the fact that it
> guarantees NUL-termination on the destination buffer without
> unnecessarily NUL-padding.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>

applied to linux-can-next/testing.

regards,
Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung Nürnberg | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |


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2023-10-05 16:17:40

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] can: peak_pci: replace deprecated strncpy with strscpy

On Thu, Oct 05, 2023 at 12:05:35AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> NUL-padding is not required since card is already zero-initialized:
> | card = kzalloc(sizeof(*card), GFP_KERNEL);
>
> A suitable replacement is `strscpy` [2] due to the fact that it
> guarantees NUL-termination on the destination buffer without
> unnecessarily NUL-padding.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>

Yup, this looks like a standard direct replacement.

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook