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Message-ID: <d3eb1d37-fcbc-e3d7-30d4-3e97aa20696b@kernel.org>
Date:   Sun, 27 Nov 2022 12:39:03 -0700
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Subject: Re: [PATCH 1/2] udp_tunnel: Add checks for nla_nest_start() in
 __udp_tunnel_nic_dump_write()
Content-Language: en-US
To:     Yuan Can <yuancan@huawei.com>, johannes@sipsolutions.net,
        davem@davemloft.net, yoshfuji@linux-ipv6.org, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, linux-wireless@vger.kernel.org,
        netdev@vger.kernel.org
References: <20221126100634.106887-1-yuancan@huawei.com>
 <20221126100634.106887-2-yuancan@huawei.com>
From:   David Ahern <dsahern@kernel.org>
In-Reply-To: <20221126100634.106887-2-yuancan@huawei.com>
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Precedence: bulk

On 11/26/22 3:06 AM, Yuan Can wrote:
> As the nla_nest_start() may fail with NULL returned, the return value needs
> to be checked.
> 
> Fixes: c7d759eb7b12 ("ethtool: add tunnel info interface")
> Signed-off-by: Yuan Can <yuancan@huawei.com>
> ---
>  net/ipv4/udp_tunnel_nic.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/ipv4/udp_tunnel_nic.c b/net/ipv4/udp_tunnel_nic.c
> index bc3a043a5d5c..75a0caa4aebe 100644
> --- a/net/ipv4/udp_tunnel_nic.c
> +++ b/net/ipv4/udp_tunnel_nic.c
> @@ -624,6 +624,8 @@ __udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
>  			continue;
>  
>  		nest = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY);
> +		if (!nest)
> +			goto err_cancel;

no need to call nla_nest_cancel if nest_start fails.

>  
>  		if (nla_put_be16(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT,
>  				 utn->entries[table][j].port) ||