`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
We expect `dst` to be NUL-terminated based on its use with format
strings:
| mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst);
Moreover, NUL-padding is not required.
Considering the above, 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.
Found with: $ rg "strncpy\("
---
drivers/net/ethernet/mellanox/mlx4/fw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/fw.c b/drivers/net/ethernet/mellanox/mlx4/fw.c
index fe48d20d6118..0005d9e2c2d6 100644
--- a/drivers/net/ethernet/mellanox/mlx4/fw.c
+++ b/drivers/net/ethernet/mellanox/mlx4/fw.c
@@ -1967,7 +1967,7 @@ int mlx4_INIT_HCA(struct mlx4_dev *dev, struct mlx4_init_hca_param *param)
if (dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_DRIVER_VERSION_TO_FW) {
u8 *dst = (u8 *)(inbox + INIT_HCA_DRIVER_VERSION_OFFSET / 4);
- strncpy(dst, DRV_NAME_FOR_FW, INIT_HCA_DRIVER_VERSION_SZ - 1);
+ strscpy(dst, DRV_NAME_FOR_FW, INIT_HCA_DRIVER_VERSION_SZ);
mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst);
}
---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231011-strncpy-drivers-net-ethernet-mellanox-mlx4-fw-c-67809559dd1a
Best regards,
--
Justin Stitt <[email protected]>
On Wed, Oct 11, 2023 at 09:04:37PM +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.
>
> We expect `dst` to be NUL-terminated based on its use with format
> strings:
> | mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst);
>
> Moreover, NUL-padding is not required.
Yup, since it's only use is for the above report.
>
> Considering the above, 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]>
Thanks!
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
On 11 Oct 21:04, 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.
>
>We expect `dst` to be NUL-terminated based on its use with format
>strings:
>| mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst);
>
>Moreover, NUL-padding is not required.
>
>Considering the above, 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.
>
>Found with: $ rg "strncpy\("
>---
> drivers/net/ethernet/mellanox/mlx4/fw.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/net/ethernet/mellanox/mlx4/fw.c b/drivers/net/ethernet/mellanox/mlx4/fw.c
>index fe48d20d6118..0005d9e2c2d6 100644
>--- a/drivers/net/ethernet/mellanox/mlx4/fw.c
>+++ b/drivers/net/ethernet/mellanox/mlx4/fw.c
>@@ -1967,7 +1967,7 @@ int mlx4_INIT_HCA(struct mlx4_dev *dev, struct mlx4_init_hca_param *param)
> if (dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_DRIVER_VERSION_TO_FW) {
> u8 *dst = (u8 *)(inbox + INIT_HCA_DRIVER_VERSION_OFFSET / 4);
>
>- strncpy(dst, DRV_NAME_FOR_FW, INIT_HCA_DRIVER_VERSION_SZ - 1);
>+ strscpy(dst, DRV_NAME_FOR_FW, INIT_HCA_DRIVER_VERSION_SZ);
> mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst);
> }
>
>
>---
>base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
>change-id: 20231011-strncpy-drivers-net-ethernet-mellanox-mlx4-fw-c-67809559dd1a
>
>Best regards,
>--
>Justin Stitt <[email protected]>
>
Reviewed-by: Saeed Mahameed <[email protected]>
Hello:
This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[email protected]>:
On Wed, 11 Oct 2023 21:04:37 +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.
>
> We expect `dst` to be NUL-terminated based on its use with format
> strings:
> | mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst);
>
> [...]
Here is the summary with links:
- net/mlx4_core: replace deprecated strncpy with strscpy
https://git.kernel.org/netdev/net-next/c/88fca39b660b
You are awesome, thank you!
--
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