From: Cong Wang <xiyou.wangcong@gmail.com>

Date: Wed, 31 Jan 2018 15:02:47 -0800

Subject: netfilter: xt_cgroup: initialize info->priv in cgroup_mt_check_v1()

Patch-mainline: v4.16-rc1

Git-commit: ba7cd5d95f25cc6005f687dabdb4e7a6063adda9

References: bsc#1076830

xt_cgroup_info_v1->priv is an internal pointer only used for kernel,

we should not trust what user-space provides.

Reported-by: <syzbot+4fbcfcc0d2e6592bd641@syzkaller.appspotmail.com>

Fixes: c38c4597e4bf ("netfilter: implement xt_cgroup cgroup2 path match")

Cc: Pablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Acked-by: Michal Kubecek <mkubecek@suse.cz>

---

 net/netfilter/xt_cgroup.c | 1 +

 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/xt_cgroup.c b/net/netfilter/xt_cgroup.c

index 1db1ce59079f..891f4e7e8ea7 100644

--- a/net/netfilter/xt_cgroup.c

+++ b/net/netfilter/xt_cgroup.c

@@ -52,6 +52,7 @@ static int cgroup_mt_check_v1(const struct xt_mtchk_param *par)

 		return -EINVAL;

 	}

+	info->priv = NULL;

 	if (info->has_path) {

 		cgrp = cgroup_get_from_path(info->path);

 		if (IS_ERR(cgrp)) {

-- 

2.16.2