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Date:   Tue, 17 Oct 2023 23:30:12 +0000
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Message-ID: <20231017-strncpy-drivers-net-wireless-ti-wl1251-main-c-v1-1-3a5c02382e35@google.com>
Subject: [PATCH] wifi: mac80211: replace deprecated strncpy with strscpy
From:   Justin Stitt <justinstitt@google.com>
To:     Kalle Valo <kvalo@kernel.org>
Cc:     linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        Justin Stitt <justinstitt@google.com>
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Precedence: bulk

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>
---
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>