From e3bbab4754dec801cefdd1b55920aff1bffac09d Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Tue, 10 Oct 2023 22:32:35 +0000 Subject: [PATCH] net: dsa: vsc73xx: replace deprecated strncpy with ethtool_sprintf `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. This change could result in misaligned strings when if(cnt) fails. To combat this, use ternary to place empty string in buffer and properly increment pointer to next string slot. 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 Signed-off-by: Justin Stitt Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231010-strncpy-drivers-net-dsa-vitesse-vsc73xx-core-c-v2-1-ba4416a9ff23@google.com Signed-off-by: Jakub Kicinski --- drivers/net/dsa/vitesse-vsc73xx-core.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c index 35a846d7e13f..e6f29e4e508c 100644 --- a/drivers/net/dsa/vitesse-vsc73xx-core.c +++ b/drivers/net/dsa/vitesse-vsc73xx-core.c @@ -928,7 +928,8 @@ static void vsc73xx_get_strings(struct dsa_switch *ds, int port, u32 stringset, const struct vsc73xx_counter *cnt; struct vsc73xx *vsc = ds->priv; u8 indices[6]; - int i, j; + u8 *buf = data; + int i; u32 val; int ret; @@ -948,10 +949,7 @@ static void vsc73xx_get_strings(struct dsa_switch *ds, int port, u32 stringset, indices[5] = ((val >> 26) & 0x1f); /* TX counter 2 */ /* The first counters is the RX octets */ - j = 0; - strncpy(data + j * ETH_GSTRING_LEN, - "RxEtherStatsOctets", ETH_GSTRING_LEN); - j++; + ethtool_sprintf(&buf, "RxEtherStatsOctets"); /* Each port supports recording 3 RX counters and 3 TX counters, * figure out what counters we use in this set-up and return the @@ -961,23 +959,16 @@ static void vsc73xx_get_strings(struct dsa_switch *ds, int port, u32 stringset, */ for (i = 0; i < 3; i++) { cnt = vsc73xx_find_counter(vsc, indices[i], false); - if (cnt) - strncpy(data + j * ETH_GSTRING_LEN, - cnt->name, ETH_GSTRING_LEN); - j++; + ethtool_sprintf(&buf, "%s", cnt ? cnt->name : ""); } /* TX stats begins with the number of TX octets */ - strncpy(data + j * ETH_GSTRING_LEN, - "TxEtherStatsOctets", ETH_GSTRING_LEN); - j++; + ethtool_sprintf(&buf, "TxEtherStatsOctets"); for (i = 3; i < 6; i++) { cnt = vsc73xx_find_counter(vsc, indices[i], true); - if (cnt) - strncpy(data + j * ETH_GSTRING_LEN, - cnt->name, ETH_GSTRING_LEN); - j++; + ethtool_sprintf(&buf, "%s", cnt ? cnt->name : ""); + } } -- 2.34.1