[PATCH] hwmon: pmbus: refactor deprecated strncpy

From: Justin Stitt
Date: Fri Sep 15 2023 - 14:30:13 EST


`strncpy` is deprecated for use on NUL-terminated destination strings [1].

We should prefer more robust and less ambiguous string interfaces.

A suitable replacement is `strscpy` [2] due to the fact that it guarantees
NUL-termination on the destination buffer without unnecessarily NUL-padding.

`label` is zero-allocated and as such the NUL-padding behavior of
strncpy is not required here.

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@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
drivers/hwmon/pmbus/pmbus_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 1363d9f89181..dcc8b12387cc 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1394,7 +1394,7 @@ static int pmbus_add_label(struct pmbus_data *data,
snprintf(label->name, sizeof(label->name), "%s%d_label", name, seq);
if (!index) {
if (phase == 0xff)
- strncpy(label->label, lstring,
+ strscpy(label->label, lstring,
sizeof(label->label) - 1);
else
snprintf(label->label, sizeof(label->label), "%s.%d",

---
base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec
change-id: 20230915-strncpy-drivers-hwmon-pmbus-pmbus_core-c-8279663960a3

Best regards,
--
Justin Stitt <justinstitt@xxxxxxxxxx>