Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 216.228.112.34 as permitted sender) receiver=protection.outlook.com;
 client-ip=216.228.112.34; helo=mail.nvidia.com;
Subject: Re: [PATCH] net: bonding: fix error return code of bond_neigh_init()
To:     Jia-Ju Bai <baijiaju1990@gmail.com>, <j.vosburgh@gmail.com>,
        <vfalico@gmail.com>, <andy@greyhouse.net>, <davem@davemloft.net>,
        <kuba@kernel.org>
CC:     <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Saeed Mahameed <saeedm@nvidia.com>
References: <20210308031102.26730-1-baijiaju1990@gmail.com>
From:   Roi Dayan <roid@nvidia.com>
Message-ID: <e15f36f7-6421-69a3-f10a-45b83621b96f@nvidia.com>
Date:   Wed, 10 Mar 2021 11:24:20 +0200
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.0
MIME-Version: 1.0
In-Reply-To: <20210308031102.26730-1-baijiaju1990@gmail.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2021 09:24:26.4527
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: c7a5952a-9c60-4077-d757-08d8e3a64cd0
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.112.34];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT067.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR12MB3183
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 2021-03-08 5:11 AM, Jia-Ju Bai wrote:
> When slave is NULL or slave_ops->ndo_neigh_setup is NULL, no error
> return code of bond_neigh_init() is assigned.
> To fix this bug, ret is assigned with -EINVAL in these cases.
> 
> Fixes: 9e99bfefdbce ("bonding: fix bond_neigh_init()")
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
>   drivers/net/bonding/bond_main.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 74cbbb22470b..456315bef3a8 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -3978,11 +3978,15 @@ static int bond_neigh_init(struct neighbour *n)
>   
>   	rcu_read_lock();
>   	slave = bond_first_slave_rcu(bond);
> -	if (!slave)
> +	if (!slave) {
> +		ret = -EINVAL;
>   		goto out;
> +	}
>   	slave_ops = slave->dev->netdev_ops;
> -	if (!slave_ops->ndo_neigh_setup)
> +	if (!slave_ops->ndo_neigh_setup) {
> +		ret = -EINVAL;
>   		goto out;
> +	}
>   
>   	/* TODO: find another way [1] to implement this.
>   	 * Passing a zeroed structure is fragile,
> 


Hi,

This breaks basic functionally that always worked. A slave doesn't need
to exists nor to implement ndo_neigh_setup.
Now trying to add a neigh entry because of that fails.
This commit needs to be reverted.

Thanks,
Roi