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Date:   Tue, 25 Jul 2023 20:19:52 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Zheng Wang <zyytlz.wz@163.com>
Cc:     s.shtylyov@omp.ru, lee@kernel.org, linyunsheng@huawei.com,
        davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
        richardcochran@gmail.com, p.zabel@pengutronix.de,
        geert+renesas@glider.be, magnus.damm@gmail.com,
        yoshihiro.shimoda.uh@renesas.com, biju.das.jz@bp.renesas.com,
        wsa+renesas@sang-engineering.com, netdev@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
        hackerzheng666@gmail.com, 1395428693sheep@gmail.com,
        alex000young@gmail.com
Subject: Re: [PATCH v4] net: ravb: Fix possible UAF bug in ravb_remove
Message-ID: <20230725201952.2f23bb3b@kernel.org>
In-Reply-To: <20230725030026.1664873-1-zyytlz.wz@163.com>
References: <20230725030026.1664873-1-zyytlz.wz@163.com>
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On Tue, 25 Jul 2023 11:00:26 +0800 Zheng Wang wrote:
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 4d6b3b7d6abb..ce2da5101e51 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2885,6 +2885,9 @@ static int ravb_remove(struct platform_device *pdev)
>  	struct ravb_private *priv = netdev_priv(ndev);
>  	const struct ravb_hw_info *info = priv->info;
>  
> +	netif_carrier_off(ndev);
> +	netif_tx_disable(ndev);
> +	cancel_work_sync(&priv->work);

Still racy, the carrier can come back up after canceling the work.
But whatever, this is a non-issue in the first place.
The fact that ravb_tx_timeout_work doesn't take any locks seems much
more suspicious.