Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35;
Date:   Fri, 13 Oct 2023 17:56:54 +0800
From:   Hongren Zheng <i@zenithal.me>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Valentina Manea <valentina.manea.m@gmail.com>,
        Shuah Khan <shuah@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        sfr@canb.auug.org.au
Subject: Re: [PATCH v2 1/1] usbip: Use platform_device_register_full()
Message-ID: <ZSkUZpMhiwweSPX5@Sun>
References: <20231006164312.3528524-1-andriy.shevchenko@linux.intel.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20231006164312.3528524-1-andriy.shevchenko@linux.intel.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?L84h99eHXQpW63HAhy0VjuswnVF1YlpDUx+BP1jpoA3kSSqihiogpzvXlGUc?=
 =?us-ascii?Q?psvq2Y+295tWsuj6hcMFrcyEdDfOoUqQNpPvsDvJQapggwbfDmZH4VOfi/Q+?=
 =?us-ascii?Q?T9nA4wC81LyU74EBAChsHz0gQU9OYEMyHacJbhQg61NB3+i8EsCp0dvLPirc?=
 =?us-ascii?Q?ynZYS65HWvweHfCgjS4m/5mEIsr/9X7MjhO9/8HK79/c0NlsttxkdFpr6Re+?=
 =?us-ascii?Q?LCUEbHvcAvLRQJurUzM6f3hWlmIxlsSJEvxQiGOGC0XpPVGo4DxHiB7kiGio?=
 =?us-ascii?Q?gyMX9bH9uIUIdWI9l7qwLQD810OQDbbeBykhDWeG+k7avesKOYdAvH2Er9hB?=
 =?us-ascii?Q?KG6DHKefLqhkNan3+tjcq/MFzNKnRE5Q1bVGVWRZWjQM3HU/VhZqM+PR2Brl?=
 =?us-ascii?Q?SyiJMGKt53fnMIoE9Oqckn2YftqdPW7jl8NvXUa8r2W96V3nVePwJbIyiF+O?=
 =?us-ascii?Q?4eECQ8c47DbG0FAvM9gnubR0kIuWfAgE/wso1MQPVxleDllOSYZUiph/ukOw?=
 =?us-ascii?Q?7CPczibjRAyurd7p5PQ3/nQD3uxBIs3qg7e1Y830cmYIFqTQdtWLn3mG+ES7?=
 =?us-ascii?Q?ywRk8uJFq8Ui7CK5rRCAoI7Msc/iFo7LamPbRt6CRyVpqbCy5MEIwVME/q+7?=
 =?us-ascii?Q?QKS7p/l0l20dHsRgh8NavO4Zpmqr11tpLY1Ru/2CMKOIQ/v59OzfxvGD1wbh?=
 =?us-ascii?Q?Mhyfr3+X/z4t52Dy4oINy/BRwU/x4QgE1Z72fGj9zP4v3/zVhqBqbAB5seNX?=
 =?us-ascii?Q?tLIkOp2pBjaU7DQYbdpj2NLzR1kI2XahuCfkSsBt/xrZbE/KXiM+Sp1Zy2ct?=
 =?us-ascii?Q?QwekpDy63U7NUNPdK0/hnbg0O/gPGtr0AaF8dlr6qc7i15egSgsWgyOm95N5?=
 =?us-ascii?Q?qW3s1VoIMdTDCviGD1Hp9N9/vmcoibSXwRB5UCHDflpjwuhlLcCr/RrGjX66?=
 =?us-ascii?Q?tYoO/OayJ7os/13mSn6XytPpnlo4y90xezuOBbfH6OCgn+wIXbdD7zcVBvwM?=
 =?us-ascii?Q?G14/XO/B6sluYc8v9YOoDStZr/c+mAYb2htC+JoI9CMzODwVdjjRiZp9OoSY?=
 =?us-ascii?Q?yg9r7LCQXlYN04YLW+5rxWLKx/NoQ9RDsVoBzBSzN23/iy3+xi3N1OBVAQH9?=
 =?us-ascii?Q?9DzGIdxfPmRt5fKRyGKCjY+uAnHWCoEjHrRPZwG6K8A/Er9mLbZga80SFrj7?=
 =?us-ascii?Q?CwRe/2rxEQML+tRnojVSjQM/u64Bg35VT5NFjEOREhsoeBIUlFfp4s1ORexC?=
 =?us-ascii?Q?Ps/q5/ABnNutfmNLOXP8h6eysbn+UIn+dzCtlPpviq91gGTtNFQ8T20vwBbx?=
 =?us-ascii?Q?vQdAAOtPGnO8mJI3jUksO0hQ0cxUVqEO5LFX8UPnkM+1FEM42XC8PgtVZbx2?=
 =?us-ascii?Q?AujyK7i8jHoqNI7IK0uF2KrXkPOH5pVNBAyiH4oNPUF8Es/gXxK/bYAEJQ6+?=
 =?us-ascii?Q?KVuqNNdhwPRH8LGTBIEZLzhGxpOVK+fo77CuSVN8Ed1AkCAnQLvG69GfBWSI?=
 =?us-ascii?Q?5Dn6sSnorvoIg6EcNZHaxBKDTUUjCUU0D38ZvNi/7tIYetK0vjtPlhP4wXuC?=
 =?us-ascii?Q?x3OsVYmCaOk8eThRJ5GFxhftOaUE1rr2DsQERHu7?=
X-OriginatorOrg: zenithal.me
X-MS-Exchange-CrossTenant-Network-Message-Id: 4666718b-e5cf-4384-918e-08dbcbd2bf32
X-MS-Exchange-CrossTenant-AuthSource: TYYP286MB1406.JPNP286.PROD.OUTLOOK.COM
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Oct 2023 09:57:01.6599
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 436d481c-43b1-4418-8d7f-84c1e4887cf0
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: R/0040w9nAjiP8D9NeUNx7T224s0mKz91qrR9EUwtxm1f2UgB+XzAgOZtSGR/9Sv
X-MS-Exchange-Transport-CrossTenantHeadersStamped: OSZP286MB1943
X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
	DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,
	SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no
	version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on groat.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (groat.vger.email [0.0.0.0]); Fri, 13 Oct 2023 02:57:17 -0700 (PDT)

On Fri, Oct 06, 2023 at 07:43:12PM +0300, Andy Shevchenko wrote:
> The code to create the child platform device is essentially the same as
> what platform_device_register_full() does, so change over to use
> that same function to reduce duplication.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> v2: (hopefully) fixed run-time NULL-dereference (LKP)
>  drivers/usb/usbip/vhci_hcd.c | 55 +++++++++++++-----------------------
>  1 file changed, 20 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
> index 37d1fc34e8a5..f845b91848b9 100644
> --- a/drivers/usb/usbip/vhci_hcd.c
> +++ b/drivers/usb/usbip/vhci_hcd.c
  
> -	for (i = 0; i < vhci_num_controllers; i++) {
> -		void *vhci = &vhcis[i];

The void *vhci here is intended

platform_device_add_data "Add a copy of platform specific data to the
platform device's platform_data pointer"

however, vhcis is static so it is not intended to be copied (the
pdev inside struct vhci might be the cause)

> -		ret = platform_device_add_data(vhcis[i].pdev, &vhci, sizeof(void *));
> -		if (ret)
> -			goto err_driver_register;
> -	}
> -
>  	ret = platform_driver_register(&vhci_driver);
>  	if (ret)
>  		goto err_driver_register;
>  
>  	for (i = 0; i < vhci_num_controllers; i++) {
> -		ret = platform_device_add(vhcis[i].pdev);
> +		struct platform_device_info pdevinfo = {
> +			.name = driver_name,
> +			.id = i,
> +			.data = &vhcis[i],

here should be a &vhci

> +			.size_data = sizeof(void *),
> +		};
> +
> +		vhcis[i].pdev = platform_device_register_full(&pdevinfo);
> +		ret = PTR_ERR_OR_ZERO(vhcis[i].pdev);
>  }
> -- 
> 2.40.0.1.gaa8946217a0b

I have reproduced the boot error reported by syzbot in
https://lore.kernel.org/linux-usb/00000000000029242706077f3145@google.com/
https://lore.kernel.org/linux-usb/0000000000007634c1060793197c@google.com/

and adding back void *vhci fixed it

I'll send a patch.