hwmon: (asus_wmi_sensors) Replace deprecated strncpy() with strscpy()

`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. If, for any reason, NUL-padding is needed
let's opt for `strscpy_pad`.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230914-strncpy-drivers-hwmon-asus_wmi_sensors-c-v1-1-e1703cf91693@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/drivers/hwmon/asus_wmi_sensors.c b/drivers/hwmon/asus_wmi_sensors.c
index 6e8a908171f0aa99396454fff3c3a5042dde6b41..c2dd7ff882f24bba840afd12c238bb55b9c845ed 100644 (file)
--- a/drivers/hwmon/asus_wmi_sensors.c
+++ b/drivers/hwmon/asus_wmi_sensors.c
@@ -300,7 +300,7 @@ static int asus_wmi_sensor_info(int index, struct asus_wmi_sensor_info *s)
                goto out_free_obj;
        }
 
-       strncpy(s->name, name_obj.string.pointer, sizeof(s->name) - 1);
+       strscpy(s->name, name_obj.string.pointer, sizeof(s->name));
 
        data_type_obj = obj->package.elements[1];
        if (data_type_obj.type != ACPI_TYPE_INTEGER) {