netfilter: xt_helper: Use sizeof(variable) instead of literal number

It's better to use sizeof(info->name)-1 as index to force set the string
tail instead of literal number '29'.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/xt_helper.c b/net/netfilter/xt_helper.c
index 9f4ab00..805c9f6 100644 (file)
--- a/net/netfilter/xt_helper.c
+++ b/net/netfilter/xt_helper.c
@@ -65,7 +65,7 @@ static int helper_mt_check(const struct xt_mtchk_param *par)
                        par->family);
                return ret;
        }
-       info->name[29] = '\0';
+       info->name[sizeof(info->name) - 1] = '\0';
        return 0;
 }