Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
Date:   Thu, 05 Oct 2023 20:51:40 +0000
Mime-Version: 1.0
Message-ID: <20231005-strncpy-drivers-net-ethernet-broadcom-bcm63xx_enet-c-v1-1-6823b3c3c443@google.com>
Subject: [PATCH] bcm63xx_enet: replace deprecated strncpy with strscpy
From:   Justin Stitt <justinstitt@google.com>
To:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        Justin Stitt <justinstitt@google.com>
Content-Type: text/plain; charset="utf-8"
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.

A suitable replacement is strscpy() [2] due to the fact that it
guarantees NUL-termination on the destination buffer without
unnecessarily NUL-padding.

bcm_enet_get_drvinfo() already uses strscpy(), let's match it's
implementation:
|       static void bcm_enet_get_drvinfo(struct net_device *netdev,
|       				 struct ethtool_drvinfo *drvinfo)
|       {
|       	strscpy(drvinfo->driver, bcm_enet_driver_name, sizeof(drvinfo->driver));
|       	strscpy(drvinfo->bus_info, "bcm63xx", sizeof(drvinfo->bus_info));
|       }

Note that now bcm_enet_get_drvinfo() and bcm_enetsw_get_drvinfo() do the
exact same thing.

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: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
 drivers/net/ethernet/broadcom/bcm63xx_enet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index a741070f1f9a..8b18493759bf 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -2531,8 +2531,8 @@ static int bcm_enetsw_get_sset_count(struct net_device *netdev,
 static void bcm_enetsw_get_drvinfo(struct net_device *netdev,
 				   struct ethtool_drvinfo *drvinfo)
 {
-	strncpy(drvinfo->driver, bcm_enet_driver_name, sizeof(drvinfo->driver));
-	strncpy(drvinfo->bus_info, "bcm63xx", sizeof(drvinfo->bus_info));
+	strscpy(drvinfo->driver, bcm_enet_driver_name, sizeof(drvinfo->driver));
+	strscpy(drvinfo->bus_info, "bcm63xx", sizeof(drvinfo->bus_info));
 }
 
 static void bcm_enetsw_get_ethtool_stats(struct net_device *netdev,

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231005-strncpy-drivers-net-ethernet-broadcom-bcm63xx_enet-c-0a95cd331460

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