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Date:   Mon, 28 Feb 2022 08:51:46 +0100
From:   Marc Kleine-Budde <mkl@pengutronix.de>
To:     Hangyu Hua <hbh25y@gmail.com>
Cc:     wg@grandegger.com, davem@davemloft.net, kuba@kernel.org,
        stefan.maetje@esd.eu, mailhol.vincent@wanadoo.fr,
        paskripkin@gmail.com, thunder.leizhen@huawei.com,
        linux-can@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] can: usb: fix a possible memory leak in
 esd_usb2_start_xmit
Message-ID: <20220228075146.hvui3iow7niupij4@pengutronix.de>
References: <20220225060019.21220-1-hbh25y@gmail.com>
 <20220225155621.7zmfukra63qcxjo5@pengutronix.de>
 <69b0dd44-93ac-fa33-f9c1-6f787185ab47@gmail.com>
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On 28.02.2022 10:05:03, Hangyu Hua wrote:
> I get it. But this means ems_usb_start_xmit have a redundant
> dev_kfree_skb beacause can_put_echo_skb delete original skb and
> can_free_echo_skb delete the cloned skb. While this code is harmless
> do you think we need to delete it ?

ACK. This dev_kfree_skb() should be deleted:

| 	err =3D usb_submit_urb(urb, GFP_ATOMIC);
| 	if (unlikely(err)) {
| 		can_free_echo_skb(netdev, context->echo_index, NULL);
|=20
| 		usb_unanchor_urb(urb);
| 		usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
| 		dev_kfree_skb(skb);

Can you create a patch?

regards,
Marc

--=20
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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