| Message ID | 20231011-strncpy-drivers-net-ethernet-mellanox-mlx5-core-main-c-v1-1-90fa39998bb2@google.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | net/mlx5: simplify mlx5_set_driver_version string assignments | expand |
On Wed, Oct 11, 2023 at 09:29:57PM +0000, Justin Stitt wrote: > In total, just assigning this version string takes: > (1) strncpy()'s > (5) strlen()'s > (3) strncat()'s > (1) snprintf()'s > (4) max_t()'s > > Moreover, `strncpy` is deprecated [1] and `strncat` really shouldn't be > used either [2]. With this in mind, let's simply use a single > `snprintf`. Yes, please! readability++ > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://elixir.bootlin.com/linux/v6.6-rc5/source/include/linux/fortify-string.h#L448 [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Cc: Kees Cook <keescook@chromium.org> > Signed-off-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Kees Cook <keescook@chromium.org>
On 11 Oct 14:34, Kees Cook wrote: >On Wed, Oct 11, 2023 at 09:29:57PM +0000, Justin Stitt wrote: >> In total, just assigning this version string takes: >> (1) strncpy()'s >> (5) strlen()'s >> (3) strncat()'s >> (1) snprintf()'s >> (4) max_t()'s >> >> Moreover, `strncpy` is deprecated [1] and `strncat` really shouldn't be >> used either [2]. With this in mind, let's simply use a single >> `snprintf`. > >Yes, please! readability++ > >> >> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] >> Link: https://elixir.bootlin.com/linux/v6.6-rc5/source/include/linux/fortify-string.h#L448 [2] >> Link: https://github.com/KSPP/linux/issues/90 >> Cc: linux-hardening@vger.kernel.org >> Cc: Kees Cook <keescook@chromium.org> >> Signed-off-by: Justin Stitt <justinstitt@google.com> > >Reviewed-by: Kees Cook <keescook@chromium.org> Applied to net-next-mlx5.
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c index 15561965d2af..0c829b6d2b49 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c @@ -218,7 +218,6 @@ static void mlx5_set_driver_version(struct mlx5_core_dev *dev) int driver_ver_sz = MLX5_FLD_SZ_BYTES(set_driver_version_in, driver_version); u8 in[MLX5_ST_SZ_BYTES(set_driver_version_in)] = {}; - int remaining_size = driver_ver_sz; char *string; if (!MLX5_CAP_GEN(dev, driver_version)) @@ -226,22 +225,9 @@ static void mlx5_set_driver_version(struct mlx5_core_dev *dev) string = MLX5_ADDR_OF(set_driver_version_in, in, driver_version); - strncpy(string, "Linux", remaining_size); - - remaining_size = max_t(int, 0, driver_ver_sz - strlen(string)); - strncat(string, ",", remaining_size); - - remaining_size = max_t(int, 0, driver_ver_sz - strlen(string)); - strncat(string, KBUILD_MODNAME, remaining_size); - - remaining_size = max_t(int, 0, driver_ver_sz - strlen(string)); - strncat(string, ",", remaining_size); - - remaining_size = max_t(int, 0, driver_ver_sz - strlen(string)); - - snprintf(string + strlen(string), remaining_size, "%u.%u.%u", - LINUX_VERSION_MAJOR, LINUX_VERSION_PATCHLEVEL, - LINUX_VERSION_SUBLEVEL); + snprintf(string, driver_ver_sz, "Linux,%s,%u.%u.%u", + KBUILD_MODNAME, LINUX_VERSION_MAJOR, + LINUX_VERSION_PATCHLEVEL, LINUX_VERSION_SUBLEVEL); /*Send the command*/ MLX5_SET(set_driver_version_in, in, opcode,
In total, just assigning this version string takes: (1) strncpy()'s (5) strlen()'s (3) strncat()'s (1) snprintf()'s (4) max_t()'s Moreover, `strncpy` is deprecated [1] and `strncat` really shouldn't be used either [2]. With this in mind, let's simply use a single `snprintf`. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://elixir.bootlin.com/linux/v6.6-rc5/source/include/linux/fortify-string.h#L448 [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Justin Stitt <justinstitt@google.com> --- Note: build-tested only. Found with: $ rg "strncpy\(" --- drivers/net/ethernet/mellanox/mlx5/core/main.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20231011-strncpy-drivers-net-ethernet-mellanox-mlx5-core-main-c-2dd9a3fa22e0 Best regards, -- Justin Stitt <justinstitt@google.com>