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>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/netfilter/xt_helper.c b/net/netfilter/xt_helper.c
index 9f4ab00c8050..805c9f64a04c 100644
--- 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;
 }