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Date:   Sat, 27 Jul 2019 13:27:23 -0700 (PDT)
Message-Id: <20190727.132723.666166803498081831.davem@davemloft.net>
To:     baijiaju1990@gmail.com
Cc:     kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] net: ipv6: Fix a possible null-pointer dereference
 in vti6_link_config()
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20190726080321.4466-1-baijiaju1990@gmail.com>
References: <20190726080321.4466-1-baijiaju1990@gmail.com>
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From: Jia-Ju Bai <baijiaju1990@gmail.com>
Date: Fri, 26 Jul 2019 16:03:21 +0800

> @@ -646,9 +646,10 @@ static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu)
>  						 &p->raddr, &p->laddr,
>  						 p->link, NULL, strict);
>  
> -		if (rt)
> +		if (rt) {
>  			tdev = rt->dst.dev;
> -		ip6_rt_put(rt);
> +			ip6_rt_put(rt);
> +		}

ip6_rt_put() can take a NULL argument without any problem.

I want to make it clear that because of mistakes of this nature, and
how frequently you make them, it is very tiring and exhausting to
review your changes...