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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Kees Cook , Nick Desaulniers Content-Type: text/plain; charset="utf-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable `strncpy` is deprecated for use on NUL-terminated destination strings [1]. Even call sites utilizing length-bounded destination buffers should switch over to using `strtomem` or `strtomem_pad`. In this case, however, the compiler is unable to determine the size of the `data` buffer which renders `strtomem` unusable. Due to this, `strscpy` should be used. It should be noted that most call sites already zero-initialize the destination buffer. However, I've opted to use `strscpy_pad` to maintain the same exact behavior that `strncpy` produced (zero-padded tail up to `len`). Also see [3]. [1]: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-= terminated-strings [2]: elixir.bootlin.com/linux/v6.3/source/net/ethtool/ioctl.c#L1944 [3]: manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html Link: https://github.com/KSPP/linux/issues/90 Signed-off-by: Justin Stitt Reviewed-by: Kees Cook Reviewed-by: Nick Desaulniers --- net/dsa/slave.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 527b1d576460..c9f77b7e5895 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -1056,10 +1056,10 @@ static void dsa_slave_get_strings(struct net_device= *dev, if (stringset =3D=3D ETH_SS_STATS) { int len =3D ETH_GSTRING_LEN; =20 - strncpy(data, "tx_packets", len); - strncpy(data + len, "tx_bytes", len); - strncpy(data + 2 * len, "rx_packets", len); - strncpy(data + 3 * len, "rx_bytes", len); + strscpy_pad(data, "tx_packets", len); + strscpy_pad(data + len, "tx_bytes", len); + strscpy_pad(data + 2 * len, "rx_packets", len); + strscpy_pad(data + 3 * len, "rx_bytes", len); if (ds->ops->get_strings) ds->ops->get_strings(ds, dp->index, stringset, data + 4 * len); --- base-commit: fdf0eaf11452d72945af31804e2a1048ee1b574c change-id: 20230717-net-dsa-strncpy-844ca1111eb2 Best regards, --=20 Justin Stitt