On Thu, Sep 14, 2023 at 09:40:49PM +0000, Justin Stitt wrote: > `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-harden...@vger.kernel.org > Signed-off-by: Justin Stitt <justinst...@google.com> > --- > 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;
Yup, consumed by strlen() and snprintf(). Looks like a standard conversion. :) Reviewed-by: Kees Cook <keesc...@chromium.org> -Kees > > --- > base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec > change-id: > 20230914-strncpy-drivers-gpu-drm-nouveau-nvkm-core-firmware-c-791223838b72 > > Best regards, > -- > Justin Stitt <justinst...@google.com> > -- Kees Cook
