netfilter: x_tables: allow to use default cgroup match

There's actually no good reason why we cannot use cgroup id 0,
so lets just remove this artificial barrier.

Reported-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Tested-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/xt_cgroup.c b/net/netfilter/xt_cgroup.c
index f4e833005320fa7da4c0deb41bba272e8c54bd8e..7198d660b4dea1e9e79c6f9a13f4e6669bca569d 100644 (file)
--- a/net/netfilter/xt_cgroup.c
+++ b/net/netfilter/xt_cgroup.c
@@ -31,7 +31,7 @@ static int cgroup_mt_check(const struct xt_mtchk_param *par)
        if (info->invert & ~1)
                return -EINVAL;
 
-       return info->id ? 0 : -EINVAL;
+       return 0;
 }
 
 static bool