Messages in this thread | | | Date | Wed, 18 Oct 2023 16:23:47 -0700 | From | Kees Cook <> | Subject | Re: [PATCH] net: mdio: replace deprecated strncpy with strscpy |
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On Thu, Oct 12, 2023 at 09:53:03PM +0000, Justin Stitt wrote: > strncpy() is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > We expect mdiodev->modalias to be NUL-terminated based on its usage with > strcmp(): > | return strcmp(mdiodev->modalias, drv->name) == 0; > > Moreover, mdiodev->modalias is already zero-allocated: > | mdiodev = kzalloc(sizeof(*mdiodev), GFP_KERNEL); > ... which means the NUL-padding strncpy provides is not necessary. > > Considering the above, a suitable replacement is `strscpy` [2] due to > the fact that it guarantees NUL-termination on the destination buffer > without unnecessarily NUL-padding. > > 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@vger.kernel.org > Signed-off-by: Justin Stitt <justinstitt@google.com>
Looks good!
Reviewed-by: Kees Cook <keescook@chromium.org>
-- Kees Cook
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