`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. There is likely no bug in the current implementation due to the safeguard: | cname[sizeof(cname) - 1] = '\0'; ... however we can provide simpler and easier to understand code using the newer (and recommended) `strscpy` api. 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/gpu/drm/nouveau/nvkm/core/firmware.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/core/firmware.c b/drivers/gpu/drm/nouveau/nvkm/core/firmware.c index 91fb494d4009..374212da9e95 100644 --- a/drivers/gpu/drm/nouveau/nvkm/core/firmware.c +++ b/drivers/gpu/drm/nouveau/nvkm/core/firmware.c @@ -79,8 +79,7 @@ nvkm_firmware_get(const struct nvkm_subdev *subdev, const char *fwname, int ver, int i; /* Convert device name to lowercase */ - strncpy(cname, device->chip->name, sizeof(cname)); - cname[sizeof(cname) - 1] = '\0'; + strscpy(cname, device->chip->name, sizeof(cname)); i = strlen(cname); while (i) { --i; --- base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec change-id: 20230914-strncpy-drivers-gpu-drm-nouveau-nvkm-core-firmware-c-791223838b72 Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
