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Date:   Mon, 09 Oct 2023 23:05:41 +0000
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Message-ID: <20231009-strncpy-drivers-net-ethernet-freescale-fec_main-c-v1-1-4166833f1431@google.com>
Subject: [PATCH] net: fec: replace deprecated strncpy with ethtool_sprintf
From:   Justin Stitt <justinstitt@google.com>
To:     Wei Fang <wei.fang@nxp.com>, Shenwei Wang <shenwei.wang@nxp.com>,
        Clark Wang <xiaoning.wang@nxp.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        bpf@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.

ethtool_sprintf() is designed specifically for get_strings() usage.
Let's replace strncpy in favor of this more robust and easier to
understand interface.

Also, while we're here, let's change memcpy() over to ethtool_sprintf()
for consistency.

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/freescale/fec_main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 77c8e9cfb445..78bddcbfb5d9 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2907,12 +2907,10 @@ static void fec_enet_get_strings(struct net_device *netdev,
 	switch (stringset) {
 	case ETH_SS_STATS:
 		for (i = 0; i < ARRAY_SIZE(fec_stats); i++) {
-			memcpy(data, fec_stats[i].name, ETH_GSTRING_LEN);
-			data += ETH_GSTRING_LEN;
+			ethtool_sprintf(&data, "%s", fec_stats[i].name);
 		}
 		for (i = 0; i < ARRAY_SIZE(fec_xdp_stat_strs); i++) {
-			strncpy(data, fec_xdp_stat_strs[i], ETH_GSTRING_LEN);
-			data += ETH_GSTRING_LEN;
+			ethtool_sprintf(&data, "%s", fec_xdp_stat_strs[i]);
 		}
 		page_pool_ethtool_stats_get_strings(data);
 

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231009-strncpy-drivers-net-ethernet-freescale-fec_main-c-84f03fffa031

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