`strncpy` is deprecated for use on NUL-terminated destination strings [1]. Let's refactor this kcalloc() + strncpy() into a kmemdup_nul() which has more obvious behavior and is less error prone. 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@xxxxxxxxxxxxxxx Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> --- Changes in v4: - drop +1 from length arg (thanks Kees) - reword subject line (thanks Kees) - rebase onto 6465e260f4879080 - Link to v3: https://lore.kernel.org/r/20230921-strncpy-drivers-hwmon-acpi_power_meter-c-v3-1-307552c6ec3f@xxxxxxxxxx Changes in v3: - refactor to use kmemdup_nul() (thanks Thomas and Kees) - change commit msg to reflect ^ - rebase onto 2cf0f71562387282 - Link to v2: https://lore.kernel.org/r/20230919-strncpy-drivers-hwmon-acpi_power_meter-c-v2-1-8348432d6442@xxxxxxxxxx Changes in v2: - use memcpy over strscpy (thanks Kees) - Link to v1: https://lore.kernel.org/r/20230914-strncpy-drivers-hwmon-acpi_power_meter-c-v1-1-905297479fe8@xxxxxxxxxx --- drivers/hwmon/acpi_power_meter.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c index fa28d447f0df..c13b5c8a0433 100644 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -796,14 +796,13 @@ static int read_capabilities(struct acpi_power_meter_resource *resource) goto error; } - *str = kcalloc(element->string.length + 1, sizeof(u8), - GFP_KERNEL); + *str = kmemdup_nul(element->string.pointer, element->string.length, + GFP_KERNEL); if (!*str) { res = -ENOMEM; goto error; } - strncpy(*str, element->string.pointer, element->string.length); str++; } --- base-commit: 6465e260f48790807eef06b583b38ca9789b6072 change-id: 20230914-strncpy-drivers-hwmon-acpi_power_meter-c-c9f2d8053bef Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
