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From: William Tu <u9012063@gmail.com>
Date: Thu, 14 Dec 2017 10:47:26 -0800
Message-ID: <CALDO+SZV01yLnStC9uVw0a82T2ACFSQF-zBi2z6f5Sjnhf0fGA@mail.gmail.com>
Subject: Re: [PATCH 1/2] ip_gre: fix potential memory leak in erspan_rcv
To: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Cc: "David S. Miller" <davem@davemloft.net>,
        Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        linux-kernel@vger.kernel.org,
        Linux Kernel Network Developers <netdev@vger.kernel.org>
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On Thu, Dec 14, 2017 at 7:15 AM, Haishuang Yan
<yanhaishuang@cmss.chinamobile.com> wrote:
> If md is NULL, tun_dst must be freed, otherwise it will cause memory
> leak.
>
> Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
> Cc: William Tu <u9012063@gmail.com>
> Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
> ---
>  net/ipv4/ip_gre.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
> index d828821..9253d6f 100644
> --- a/net/ipv4/ip_gre.c
> +++ b/net/ipv4/ip_gre.c
> @@ -304,8 +304,10 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
>                                 return PACKET_REJECT;
>
>                         md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
> -                       if (!md)
> +                       if (!md) {
> +                               dst_release((struct dst_entry *)tun_dst);
>                                 return PACKET_REJECT;
> +                       }
I'm not sure about this. Maybe we don't even need to check "if (!md)"
since ip_tun_rx_dst does the memory allocation.
William