2023-10-05 21:33:43

by Justin Stitt

[permalink] [raw]
Subject: [PATCH] liquidio: replace deprecated strncpy/strcpy 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 as drvinfo is memset to 0:
| memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));

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/ethernet/cavium/liquidio/lio_ethtool.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c b/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
index 9d56181a301f..d3e07b6ed5e1 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
@@ -442,10 +442,11 @@ lio_get_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
oct = lio->oct_dev;

memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
- strcpy(drvinfo->driver, "liquidio");
- strncpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
- ETHTOOL_FWVERS_LEN);
- strncpy(drvinfo->bus_info, pci_name(oct->pci_dev), 32);
+ strscpy(drvinfo->driver, "liquidio", sizeof(drvinfo->driver));
+ strscpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
+ sizeof(drvinfo->fw_version));
+ strscpy(drvinfo->bus_info, pci_name(oct->pci_dev),
+ sizeof(drvinfo->bus_info));
}

static void
@@ -458,10 +459,11 @@ lio_get_vf_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
oct = lio->oct_dev;

memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
- strcpy(drvinfo->driver, "liquidio_vf");
- strncpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
- ETHTOOL_FWVERS_LEN);
- strncpy(drvinfo->bus_info, pci_name(oct->pci_dev), 32);
+ strscpy(drvinfo->driver, "liquidio_vf", sizeof(drvinfo->driver));
+ strscpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
+ sizeof(drvinfo->fw_version));
+ strscpy(drvinfo->bus_info, pci_name(oct->pci_dev),
+ sizeof(drvinfo->bus_info));
}

static int

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_ethtool-c-b6932c0f80f1

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


2023-10-05 23:19:08

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] liquidio: replace deprecated strncpy/strcpy with strscpy

On Thu, Oct 05, 2023 at 09:33:19PM +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 as drvinfo is memset to 0:
> | memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
>
> 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/ethernet/cavium/liquidio/lio_ethtool.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c b/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
> index 9d56181a301f..d3e07b6ed5e1 100644
> --- a/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
> +++ b/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
> @@ -442,10 +442,11 @@ lio_get_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
> oct = lio->oct_dev;
>
> memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));

struct ethtool_drvinfo {
char driver[32];
...
char fw_version[ETHTOOL_FWVERS_LEN];
char bus_info[ETHTOOL_BUSINFO_LEN];

> - strcpy(drvinfo->driver, "liquidio");
> + strscpy(drvinfo->driver, "liquidio", sizeof(drvinfo->driver));

Yup, this is basically what FORTIFY_SOURCE will do automatically to
strcpy().

> - strncpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
> - ETHTOOL_FWVERS_LEN);
> + strscpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
> + sizeof(drvinfo->fw_version));

Yup, ETHTOOL_FWVERS_LEN == sizeof(drvinfo->fw_version)

> - strncpy(drvinfo->bus_info, pci_name(oct->pci_dev), 32);
> + strscpy(drvinfo->bus_info, pci_name(oct->pci_dev),
> + sizeof(drvinfo->bus_info));

Yup, ETHTOOL_BUSINFO_LEN == sizeof(drvinfo->bus_info)

> }
>
> static void
> @@ -458,10 +459,11 @@ lio_get_vf_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
> oct = lio->oct_dev;
>
> memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
> - strcpy(drvinfo->driver, "liquidio_vf");
> - strncpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
> - ETHTOOL_FWVERS_LEN);
> - strncpy(drvinfo->bus_info, pci_name(oct->pci_dev), 32);
> + strscpy(drvinfo->driver, "liquidio_vf", sizeof(drvinfo->driver));
> + strscpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
> + sizeof(drvinfo->fw_version));
> + strscpy(drvinfo->bus_info, pci_name(oct->pci_dev),
> + sizeof(drvinfo->bus_info));
> }

Yup, looks good.

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

>
> static int
>
> ---
> base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
> change-id: 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_ethtool-c-b6932c0f80f1
>
> Best regards,
> --
> Justin Stitt <[email protected]>
>
>

--
Kees Cook

2023-10-10 02:50:35

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH] liquidio: replace deprecated strncpy/strcpy with strscpy

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[email protected]>:

On Thu, 05 Oct 2023 21:33:19 +0000 you 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 as drvinfo is memset to 0:
> | memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
>
> [...]

Here is the summary with links:
- liquidio: replace deprecated strncpy/strcpy with strscpy
https://git.kernel.org/netdev/net-next/c/52cdbea1a54a

You are awesome, thank you!
--
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