This pattern of strncpy with some pointer arithmetic setting fixed-sized intervals with string literal data is a bit weird so let's use ethtool_sprintf() as this has more obvious behavior and is less-error prone.
Nicely, we also get to drop a usage of the now deprecated strncpy() [1]. One might consider this pattern: | ethtool_sprintf(&buf, lan9303_mib[u].name); ... but this triggers a -Wformat-security warning. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Kees Cook <keesc...@chromium.org> Signed-off-by: Justin Stitt <justinst...@google.com> Suggested-by: Alexander Lobakin <aleksander.loba...@intel.com> --- Changes in v2: - use ethtool_sprintf (thanks Alexander) - Link to v1: https://lore.kernel.org/r/20231005-strncpy-drivers-net-dsa-lan9303-core-c-v1-1-5a66c5381...@google.com --- Note: build-tested only. --- drivers/net/dsa/lan9303-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c index ee67adeb2cdb..95a8e5168c2a 100644 --- a/drivers/net/dsa/lan9303-core.c +++ b/drivers/net/dsa/lan9303-core.c @@ -1007,14 +1007,14 @@ static const struct lan9303_mib_desc lan9303_mib[] = { static void lan9303_get_strings(struct dsa_switch *ds, int port, u32 stringset, uint8_t *data) { + u8 *buf = data; unsigned int u; if (stringset != ETH_SS_STATS) return; for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++) { - strncpy(data + u * ETH_GSTRING_LEN, lan9303_mib[u].name, - ETH_GSTRING_LEN); + ethtool_sprintf(&buf, "%s", lan9303_mib[u].name); } } --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20231005-strncpy-drivers-net-dsa-lan9303-core-c-6386858e5c22 Best regards, -- Justin Stitt <justinst...@google.com>
