[Mesa-dev] [PATCH 06/12] ralloc: Use strnlen() inside of strncat()

Vladislav Egorov vegorov180 at gmail.com
Sat Jan 7 19:02:07 UTC 2017


If the str is long or isn't null-terminated, strlen() could take a lot
of time or even crash. I don't know why was it used in the first place,
maybe for platforms without strnlen(), but strnlen() is already used
inside of ralloc_strndup(), so this change should not additionally
break anything.
---
 src/util/ralloc.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/src/util/ralloc.c b/src/util/ralloc.c
index df2b1d8..08cb989 100644
--- a/src/util/ralloc.c
+++ b/src/util/ralloc.c
@@ -410,12 +410,7 @@ ralloc_strcat(char **dest, const char *str)
 bool
 ralloc_strncat(char **dest, const char *str, size_t n)
 {
-   /* Clamp n to the string length */
-   size_t str_length = strlen(str);
-   if (str_length < n)
-      n = str_length;
-
-   return cat(dest, str, n);
+   return cat(dest, str, strnlen(str, n));
 }
 
 char *
-- 
2.7.4



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