[PATCH v2 30/63] fortify: Prepare to improve strnlen() and strlen() warnings

Kees Cook
2021-08-18T06:09:06Z

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@privacyrequired.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
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