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Date:   Thu, 05 Oct 2023 21:33:19 +0000
Mime-Version: 1.0
Message-ID: <20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_ethtool-c-v1-1-ab565ab4d197@google.com>
Subject: [PATCH] liquidio: replace deprecated strncpy/strcpy with strscpy
From:   Justin Stitt <justinstitt@google.com>
To:     Derek Chickles <dchickles@marvell.com>,
        Satanand Burla <sburla@marvell.com>,
        Felix Manlunas <fmanlunas@marvell.com>,
        "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.

NUL-padding is not required as drvinfo is memset to 0:
|	memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));

A suitable replacement is `strscpy` [2] 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://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>
---
Note: build-tested only.
---
 drivers/net/ethernet/cavium/liquidio/lio_ethtool.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c b/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
index 9d56181a301f..d3e07b6ed5e1 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_ethtool.c
@@ -442,10 +442,11 @@ lio_get_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
 	oct = lio->oct_dev;
 
 	memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
-	strcpy(drvinfo->driver, "liquidio");
-	strncpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
-		ETHTOOL_FWVERS_LEN);
-	strncpy(drvinfo->bus_info, pci_name(oct->pci_dev), 32);
+	strscpy(drvinfo->driver, "liquidio", sizeof(drvinfo->driver));
+	strscpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
+		sizeof(drvinfo->fw_version));
+	strscpy(drvinfo->bus_info, pci_name(oct->pci_dev),
+		sizeof(drvinfo->bus_info));
 }
 
 static void
@@ -458,10 +459,11 @@ lio_get_vf_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
 	oct = lio->oct_dev;
 
 	memset(drvinfo, 0, sizeof(struct ethtool_drvinfo));
-	strcpy(drvinfo->driver, "liquidio_vf");
-	strncpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
-		ETHTOOL_FWVERS_LEN);
-	strncpy(drvinfo->bus_info, pci_name(oct->pci_dev), 32);
+	strscpy(drvinfo->driver, "liquidio_vf", sizeof(drvinfo->driver));
+	strscpy(drvinfo->fw_version, oct->fw_info.liquidio_firmware_version,
+		sizeof(drvinfo->fw_version));
+	strscpy(drvinfo->bus_info, pci_name(oct->pci_dev),
+		sizeof(drvinfo->bus_info));
 }
 
 static int

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_ethtool-c-b6932c0f80f1

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