Messages in this thread | | | Date | Thu, 12 Oct 2023 12:03:32 -0700 | From | Kees Cook <> | Subject | Re: [PATCH v2] qed: replace uses of strncpy |
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On Thu, Oct 12, 2023 at 06:35:41PM +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. > > This patch eliminates three uses of strncpy(): > > Firstly, `dest` is expected to be NUL-terminated which is evident by the > manual setting of a NUL-byte at size - 1. For this use specifically, > strscpy() is a viable replacement due to the fact that it guarantees > NUL-termination on the destination buffer. > > The next two cases should simply be memcpy() as the size of the src > string is always 3 and the destination string just wants the first 3 > bytes changed. > > To be clear, there are no buffer overread bugs in the current code as > the sizes and offsets are carefully managed such that buffers are > NUL-terminated. However, with these changes, the code is now more robust > and less ambiguous (and hopefully easier to read). > > 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 > Cc: Kees Cook <keescook@chromium.org> > Signed-off-by: Justin Stitt <justinstitt@google.com>
Yup, this looks good to me now. Thanks!
Reviewed-by: Kees Cook <keescook@chromium.org>
-- Kees Cook
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