strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
Based on the deliberate `sizeof(dest) ... - 1` pattern we can see that
both dump_info->dev_human_readable and dump_info->bus_human_readable are
intended to be NUL-terminated.
Moreover, since this seems to cross the file boundary let's NUL-pad to
ensure no behavior change.
strscpy_pad() covers both the NUL-termination and NUL-padding, let's use
it.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
---
Changes in v2:
- prefer strscpy_pad (thanks Kees)
- Link to v1: https://lore.kernel.org/r/20231017-strncpy-drivers-net-wireless-intel-iwlwifi-fw-dbg-c-v1-1-bf69ec7d1b97@google.com
---
Note: build-tested only.
Found with: $ rg "strncpy\("
---
drivers/net/wireless/intel/iwlwifi/fw/dbg.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
index 3ab6a68f1e9f..7aa282592cdc 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
@@ -880,10 +880,10 @@ iwl_fw_error_dump_file(struct iwl_fw_runtime *fwrt,
cpu_to_le32(fwrt->trans->hw_rev_step);
memcpy(dump_info->fw_human_readable, fwrt->fw->human_readable,
sizeof(dump_info->fw_human_readable));
- strncpy(dump_info->dev_human_readable, fwrt->trans->name,
- sizeof(dump_info->dev_human_readable) - 1);
- strncpy(dump_info->bus_human_readable, fwrt->dev->bus->name,
- sizeof(dump_info->bus_human_readable) - 1);
+ strscpy_pad(dump_info->dev_human_readable, fwrt->trans->name,
+ sizeof(dump_info->dev_human_readable));
+ strscpy_pad(dump_info->bus_human_readable, fwrt->dev->bus->name,
+ sizeof(dump_info->bus_human_readable));
dump_info->num_of_lmacs = fwrt->smem_cfg.num_lmacs;
dump_info->lmac_err_id[0] =
cpu_to_le32(fwrt->dump.lmac_err_id[0]);
---
base-commit: 58720809f52779dc0f08e53e54b014209d13eebb
change-id: 20231017-strncpy-drivers-net-wireless-intel-iwlwifi-fw-dbg-c-1f49f00b8a2e
Best regards,
--
Justin Stitt <[email protected]>
On Thu, Oct 19, 2023 at 05:44:59PM +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.
>
> Based on the deliberate `sizeof(dest) ... - 1` pattern we can see that
> both dump_info->dev_human_readable and dump_info->bus_human_readable are
> intended to be NUL-terminated.
>
> Moreover, since this seems to cross the file boundary let's NUL-pad to
> ensure no behavior change.
>
> strscpy_pad() covers both the NUL-termination and NUL-padding, let's use
> it.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
Thread ping. Can the wireless folks please pick this up?
Thanks!
-Kees
> ---
> Changes in v2:
> - prefer strscpy_pad (thanks Kees)
> - Link to v1: https://lore.kernel.org/r/20231017-strncpy-drivers-net-wireless-intel-iwlwifi-fw-dbg-c-v1-1-bf69ec7d1b97@google.com
> ---
> Note: build-tested only.
>
> Found with: $ rg "strncpy\("
> ---
> drivers/net/wireless/intel/iwlwifi/fw/dbg.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
> index 3ab6a68f1e9f..7aa282592cdc 100644
> --- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
> +++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
> @@ -880,10 +880,10 @@ iwl_fw_error_dump_file(struct iwl_fw_runtime *fwrt,
> cpu_to_le32(fwrt->trans->hw_rev_step);
> memcpy(dump_info->fw_human_readable, fwrt->fw->human_readable,
> sizeof(dump_info->fw_human_readable));
> - strncpy(dump_info->dev_human_readable, fwrt->trans->name,
> - sizeof(dump_info->dev_human_readable) - 1);
> - strncpy(dump_info->bus_human_readable, fwrt->dev->bus->name,
> - sizeof(dump_info->bus_human_readable) - 1);
> + strscpy_pad(dump_info->dev_human_readable, fwrt->trans->name,
> + sizeof(dump_info->dev_human_readable));
> + strscpy_pad(dump_info->bus_human_readable, fwrt->dev->bus->name,
> + sizeof(dump_info->bus_human_readable));
> dump_info->num_of_lmacs = fwrt->smem_cfg.num_lmacs;
> dump_info->lmac_err_id[0] =
> cpu_to_le32(fwrt->dump.lmac_err_id[0]);
>
> ---
> base-commit: 58720809f52779dc0f08e53e54b014209d13eebb
> change-id: 20231017-strncpy-drivers-net-wireless-intel-iwlwifi-fw-dbg-c-1f49f00b8a2e
>
> Best regards,
> --
> Justin Stitt <[email protected]>
>
--
Kees Cook
Kees Cook <[email protected]> writes:
> On Thu, Oct 19, 2023 at 05:44:59PM +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.
>>
>> Based on the deliberate `sizeof(dest) ... - 1` pattern we can see that
>> both dump_info->dev_human_readable and dump_info->bus_human_readable are
>> intended to be NUL-terminated.
>>
>> Moreover, since this seems to cross the file boundary let's NUL-pad to
>> ensure no behavior change.
>>
>> strscpy_pad() covers both the NUL-termination and NUL-padding, let's use
>> it.
>>
>> Link:
>> https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
>> [1]
>> Link: https://github.com/KSPP/linux/issues/90
>> Cc: [email protected]
>> Signed-off-by: Justin Stitt <[email protected]>
>
> Thread ping. Can the wireless folks please pick this up?
Yeah, I'll take this directly to wireless-next.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Justin Stitt <[email protected]> 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.
>
> Based on the deliberate `sizeof(dest) ... - 1` pattern we can see that
> both dump_info->dev_human_readable and dump_info->bus_human_readable are
> intended to be NUL-terminated.
>
> Moreover, since this seems to cross the file boundary let's NUL-pad to
> ensure no behavior change.
>
> strscpy_pad() covers both the NUL-termination and NUL-padding, let's use
> it.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
> Reviewed-by: Kees Cook <[email protected]>
Patch applied to wireless-next.git, thanks.
70582e26f5d9 wifi: iwlwifi: fw: replace deprecated strncpy with strscpy_pad
--
https://patchwork.kernel.org/project/linux-wireless/patch/20231019-strncpy-drivers-net-wireless-intel-iwlwifi-fw-dbg-c-v2-1-179b211a374b@google.com/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches