On Sun, Aug 22, 2021 at 12:57 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> In order to have strlen() use fortified strnlen() internally, swap their
> positions in the source. Doing this as part of later changes makes
> review difficult, so reoroder it here; no code changes.
>
> Cc: Francis Laniel <laniel_francis@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> include/linux/fortify-string.h | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
> index 68bc5978d916..a3cb1d9aacce 100644
> --- a/include/linux/fortify-string.h
> +++ b/include/linux/fortify-string.h
> @@ -56,6 +56,17 @@ __FORTIFY_INLINE char *strcat(char *p, const char *q)
> return p;
> }
>
> +extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
> +__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
> +{
> + size_t p_size = __builtin_object_size(p, 1);
> + __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
> +
> + if (p_size <= ret && maxlen != ret)
> + fortify_panic(__func__);
> + return ret;
> +}
> +
> __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
> {
> __kernel_size_t ret;
> @@ -71,17 +82,6 @@ __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
> return ret;
> }
>
> -extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
> -__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
> -{
> - size_t p_size = __builtin_object_size(p, 1);
> - __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
> -
> - if (p_size <= ret && maxlen != ret)
> - fortify_panic(__func__);
> - return ret;
> -}
> -
> /* defined after fortified strlen to reuse it */
> extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
> __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
> --
> 2.30.2
>
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--
Thanks,
~Nick Desaulniers
