[PATCH v2] wifi: wl1251: replace deprecated strncpy with strscpy

[PATCH v2] wifi: wl1251: replace deprecated strncpy with strscpy

[Justin Stitt]

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 other assignments of similar fw_version fields we can see that
NUL-termination is required but not NUL-padding:
ethernet/intel/ixgbe/ixgbe_ethtool.c
1111:   strscpy(drvinfo->fw_version, adapter->eeprom_id,
1112:           sizeof(drvinfo->fw_version));

ethernet/intel/igc/igc_ethtool.c
147:    scnprintf(adapter->fw_version,
148:              sizeof(adapter->fw_version),
153:    strscpy(drvinfo->fw_version, adapter->fw_version,
154:            sizeof(drvinfo->fw_version));

wireless/broadcom/brcm80211/brcmfmac/core.c
569:    strscpy(info->fw_version, drvr->fwver, sizeof(info->fw_version));

wireless/broadcom/brcm80211/brcmsmac/main.c
7867:           snprintf(wlc->wiphy->fw_version,
7868:                    sizeof(wlc->wiphy->fw_version), "%u.%u", rev, patch);

wireless/broadcom/b43legacy/main.c
1765:   snprintf(wiphy->fw_version, sizeof(wiphy->fw_version), "%u.%u",

wireless/broadcom/b43/main.c
2730:   snprintf(wiphy->fw_version, sizeof(wiphy->fw_version), "%u.%u",

wireless/intel/iwlwifi/dvm/main.c
1465:   snprintf(priv->hw->wiphy->fw_version,
1466:            sizeof(priv->hw->wiphy->fw_version),

wireless/intel/ipw2x00/ipw2100.c
5905:   snprintf(info->fw_version, sizeof(info->fw_version), "%s:%d:%s",

A suitable replacement is `strscpy` 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://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Changes in v2:
- fix subject (thanks Jeff)
- Link to v1: https://lore.kernel.org/r/20231017-strncpy-drivers-net-wireless-ti-wl1251-main-c-v1-1-3a5c02382e35@google.com
---
Note: build-tested only.

Found with: $ rg "strncpy\("
---
 drivers/net/wireless/ti/wl1251/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ti/wl1251/main.c b/drivers/net/wireless/ti/wl1251/main.c
index eded284af600..cd9a41f59f32 100644
--- a/drivers/net/wireless/ti/wl1251/main.c
+++ b/drivers/net/wireless/ti/wl1251/main.c
@@ -404,7 +404,7 @@ static int wl1251_op_start(struct ieee80211_hw *hw)
 
 	/* update hw/fw version info in wiphy struct */
 	wiphy->hw_version = wl->chip_id;
-	strncpy(wiphy->fw_version, wl->fw_ver, sizeof(wiphy->fw_version));
+	strscpy(wiphy->fw_version, wl->fw_ver, sizeof(wiphy->fw_version));
 
 out:
 	if (ret < 0)

---
base-commit: 58720809f52779dc0f08e53e54b014209d13eebb
change-id: 20231017-strncpy-drivers-net-wireless-ti-wl1251-main-c-6b2da81eccad

Best regards,
--
Justin Stitt <justinstitt@google.com>

Re: [PATCH v2] wifi: wl1251: replace deprecated strncpy with strscpy

[Kees Cook]

On Wed, Oct 18, 2023 at 09:15:23PM +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 other assignments of similar fw_version fields we can see that
> NUL-termination is required but not NUL-padding:
> ethernet/intel/ixgbe/ixgbe_ethtool.c
> 1111:   strscpy(drvinfo->fw_version, adapter->eeprom_id,
> 1112:           sizeof(drvinfo->fw_version));
> 
> ethernet/intel/igc/igc_ethtool.c
> 147:    scnprintf(adapter->fw_version,
> 148:              sizeof(adapter->fw_version),
> 153:    strscpy(drvinfo->fw_version, adapter->fw_version,
> 154:            sizeof(drvinfo->fw_version));
> 
> wireless/broadcom/brcm80211/brcmfmac/core.c
> 569:    strscpy(info->fw_version, drvr->fwver, sizeof(info->fw_version));
> 
> wireless/broadcom/brcm80211/brcmsmac/main.c
> 7867:           snprintf(wlc->wiphy->fw_version,
> 7868:                    sizeof(wlc->wiphy->fw_version), "%u.%u", rev, patch);
> 
> wireless/broadcom/b43legacy/main.c
> 1765:   snprintf(wiphy->fw_version, sizeof(wiphy->fw_version), "%u.%u",
> 
> wireless/broadcom/b43/main.c
> 2730:   snprintf(wiphy->fw_version, sizeof(wiphy->fw_version), "%u.%u",
> 
> wireless/intel/iwlwifi/dvm/main.c
> 1465:   snprintf(priv->hw->wiphy->fw_version,
> 1466:            sizeof(priv->hw->wiphy->fw_version),
> 
> wireless/intel/ipw2x00/ipw2100.c
> 5905:   snprintf(info->fw_version, sizeof(info->fw_version), "%s:%d:%s",
> 
> A suitable replacement is `strscpy` 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://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Yup, looks like a clean replacement.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH v2] wifi: wl1251: replace deprecated strncpy with strscpy

[Kalle Valo]

Justin Stitt <justinstitt@google.com> 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 other assignments of similar fw_version fields we can see that
> NUL-termination is required but not NUL-padding:
> ethernet/intel/ixgbe/ixgbe_ethtool.c
> 1111:   strscpy(drvinfo->fw_version, adapter->eeprom_id,
> 1112:           sizeof(drvinfo->fw_version));
> 
> ethernet/intel/igc/igc_ethtool.c
> 147:    scnprintf(adapter->fw_version,
> 148:              sizeof(adapter->fw_version),
> 153:    strscpy(drvinfo->fw_version, adapter->fw_version,
> 154:            sizeof(drvinfo->fw_version));
> 
> wireless/broadcom/brcm80211/brcmfmac/core.c
> 569:    strscpy(info->fw_version, drvr->fwver, sizeof(info->fw_version));
> 
> wireless/broadcom/brcm80211/brcmsmac/main.c
> 7867:           snprintf(wlc->wiphy->fw_version,
> 7868:                    sizeof(wlc->wiphy->fw_version), "%u.%u", rev, patch);
> 
> wireless/broadcom/b43legacy/main.c
> 1765:   snprintf(wiphy->fw_version, sizeof(wiphy->fw_version), "%u.%u",
> 
> wireless/broadcom/b43/main.c
> 2730:   snprintf(wiphy->fw_version, sizeof(wiphy->fw_version), "%u.%u",
> 
> wireless/intel/iwlwifi/dvm/main.c
> 1465:   snprintf(priv->hw->wiphy->fw_version,
> 1466:            sizeof(priv->hw->wiphy->fw_version),
> 
> wireless/intel/ipw2x00/ipw2100.c
> 5905:   snprintf(info->fw_version, sizeof(info->fw_version), "%s:%d:%s",
> 
> A suitable replacement is `strscpy` 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://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>

Patch applied to wireless-next.git, thanks.

70bd8e0d01f6 wifi: wl1251: replace deprecated strncpy with strscpy

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20231018-strncpy-drivers-net-wireless-ti-wl1251-main-c-v2-1-67b63dfcb1b8@google.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches