Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <37ae1c44-fe7e-3f0f-0eea-0c684fe04d50@suse.com>
Date:   Wed, 26 Jul 2023 10:33:22 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [PATCH] USB: add usbfs ioctl to get specific superspeedplus rates
Content-Language: en-US
To:     Dingyan Li <18500469033@163.com>,
        Greg KH <gregkh@linuxfoundation.org>
Cc:     Oliver Neukum <oneukum@suse.com>, stern@rowland.harvard.edu,
        sebastian.reichel@collabora.com, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230721084039.9728-1-18500469033@163.com>
 <2023072105-lethargic-saddling-ad97@gregkh>
 <130b453c.5c8f.1897872ce54.Coremail.18500469033@163.com>
 <2023072159-carol-underfeed-43eb@gregkh>
 <781b3f95-96e7-af83-e089-887ec7f2d255@suse.com>
 <2023072546-denture-half-5ceb@gregkh>
 <4edabcb3.7e65.1898d54679e.Coremail.18500469033@163.com>
 <ca4ad735-5605-3fd4-c903-fe5b039cf6a8@suse.com>
 <3018cd33.7ee4.1898d7e4798.Coremail.18500469033@163.com>
 <2023072526-reissue-uplifting-5674@gregkh>
 <6be59e4e.8166.1898dd22d84.Coremail.18500469033@163.com>
From:   Oliver Neukum <oneukum@suse.com>
In-Reply-To: <6be59e4e.8166.1898dd22d84.Coremail.18500469033@163.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SFZ0RVJLOTRJK1VXSk9JL1V6L3lDMm80L29vdkJ5dmdRMGIwV3hMWUUxSTdB?=
 =?utf-8?B?ZGpuVVRpTnFGNW5ZT1g1WW1yVU5MdXdURzZnRFczcmRZOTVnRVNNc015RDNz?=
 =?utf-8?B?bFFVclQ4U2V1WnJoOGNLMHJiK2tPakdXZWlOaGhjY255ZzMyMlV6WGIyR3E1?=
 =?utf-8?B?dE5PT2hsZU5jWEhEdUpoRW5LbDc0Qlk5NVNCMjdSSm1sZUdqaXNpVjY5MEtv?=
 =?utf-8?B?cS81OC9PYmpNdVl2Z200NmhrYXZCeEZLZkdjVWQ1T1JvRjBiNTJBYlFDQjQz?=
 =?utf-8?B?UGdYblBZZVdTWXpkamh2L09OSEJqZjJscVRyK3pLQSsrZkY5UytKdzJkTE5N?=
 =?utf-8?B?WHlMNXdjZ3BEOHN5NjdxSHU5RVJxVWRhMlgzUk9xblgveVN1TUpLTnB3N3Br?=
 =?utf-8?B?SllqcmR1ZmNWa296ZFFMVGd6WlNoNjh5L2Jxc1d6cE9ONzJtaGJrUVRoVDVs?=
 =?utf-8?B?RWwyOTNoZHhZemQraFRLUk5Lbm1wRVUxYVo1WVI0eDNlODQ2aFB6Y0x0d1Yz?=
 =?utf-8?B?S3cyY00yVlh4U0xVUEYrSTZYQmFWUTU5WWRXNXh0dk1VMWFONm0rYmxTUW5X?=
 =?utf-8?B?aEw5S2c4OWMxbmlOMkdtVVg4d0JPV1NTYldSR0JnaHFabE1GdzlGRWl6S1ZI?=
 =?utf-8?B?OHJhMkk4ZVlJeE00TGZwcWJOa293QXpsQ2dZSXowOEFUWXp4T09nT1c2ck1F?=
 =?utf-8?B?RU9JcW0rUUZ2N29zbUJPMU1zeFNTNFdYUmFub2Q3d29WRlR4Z0VvQ3lVNHZr?=
 =?utf-8?B?MVp4c20wc0VtYzA1TTBqdTdxbWlDNTFFNVpIQ0doZlNEUmVrMjlDM0p1WEpK?=
 =?utf-8?B?U3Z1Q29aRnJIQldUTVNyL0lXYXF0TVdlOFl1Z3loSWFUdU0wbVd0OHFrM1I1?=
 =?utf-8?B?Ym5EOURmWGJEcUo0THVNb1A1eWs3RHFSNkpkbUpudk84V0N3bXVLTmxzVVZC?=
 =?utf-8?B?Q09zdmJzMDEwSGJyWWtaV1gvSmkxenF4di9xd1RBVW5lVlUxbFppOTAxV29C?=
 =?utf-8?B?aGlGaWtETlpYWDIzMU91bTdlSnA4SzNXdEtYRkZNZFJvS3BMZy9zRjNGQTFG?=
 =?utf-8?B?SHFaWjYrSGg2dGhVTndobFAvWWEvQzhQSzJheEIyS3NYSnpVaVJWZlcxM3cv?=
 =?utf-8?B?NVNKbnJwTXV2dXkxZ2htVnBpNFovQXVEMjdNeGNZNjZsbVgxS1RURkhsWmhq?=
 =?utf-8?B?MFhLT3pDU1ZueUNjdTVwclRDWTNkZkp6U0p2Q28vU3lJZUw1dEhzcEdiRkIy?=
 =?utf-8?B?MjU3VUtaRnRoNTY4d1VSSFNZNmZEd0Q0TXZjeDFMcEtWM0lNUmZGVTVpU09p?=
 =?utf-8?B?K2Y4Zm0rR01kYlZXOEFrZVV4M2lOV0RFaXRKKzBMWFZ6dFgxLy9JeldrdHpN?=
 =?utf-8?B?TFZ6MVVyR3RPaTN3V213L1pPbEtLTUFPb3dGMms1LzBZeGJLNDcrUThmYUg5?=
 =?utf-8?B?N1BGUExrR1BLc3RtU2NLSlllRVhtZjNUcTU3a2YzcGVEa2pOVVhvRWJPZmF2?=
 =?utf-8?B?WG1uS3NkT2xrZzdPZDFtTUJIVVQ3UDNvUmJxRXBFL0R5UU9PeVZQZGk2NHo0?=
 =?utf-8?B?ZTU4Qk9ycjZHcTF1bGhCSjkwTno5aXQxK2FmV2t2ek83ZUdENWpPeDR4eFhS?=
 =?utf-8?B?MFErYWJUUHowT0QrakRacTZEengwb0U4RXdFNlMwS3VoVkdIaHE2UTg0S215?=
 =?utf-8?B?cXpCb1V6Q1h1Q0hTL2drRlZ4cVZWdGRVNmxLUHBvcHFOaUlpUzEzbVhIUkpP?=
 =?utf-8?B?Tk5FSis1UUs3eVdDZjRkTW9wVlI4SDBibEVUOWQvSk9IWE1BcVlXNXdNcDQ0?=
 =?utf-8?B?cktBK25WY3Y4eHBUcjVVZy9UVGZ4S0FIamw2aEZtN0Rudis2Y1MrUFFoVHJX?=
 =?utf-8?B?eC9kbGJmcFZBTExjY2JBbTV3dWNTVEFFbEYwdXNhNnNNLzFCUWhwSjZEdjVS?=
 =?utf-8?B?WXZHUnNQeWxyMHkvUmtaZmdIQUZmdDVKZnBaNUZxVS9VZ2VBbzlQR1V6dU8v?=
 =?utf-8?B?RkdrVy9UUW1qeXdVcWNVV3VCUTNJTjJGZ0lMbVdVckhYVlZBd1FLUGw0dlFu?=
 =?utf-8?B?YW1KNWVOUlZHdURyWEtwcnVHYnlTNUh3aDFSUm02TFlncnV3emx1MTRDMnRz?=
 =?utf-8?B?U29pdDVubEwyTG5OVzZScE9WV0tLN3VBUTNPMWgvUkNRRzZTTHhxcTUwK0FQ?=
 =?utf-8?Q?45bPPNfrzKPpBLiOOt2R7zDscjfp3urFo5iKjfiV+UHO?=
X-OriginatorOrg: suse.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 802bfcc6-7b41-4448-aac8-08db8db2fa46
X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB7104.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jul 2023 08:33:24.7164
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: WwYr7q2JuYti1UeGvI9YAUE8i6wW6Vb1pdPZRTvYMn/kUUvpVtnGqjSPRozvrpQhjxUTNVgxAVB6e/Du1j5Q+w==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VE1PR04MB7391
X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE,
        URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 25.07.23 18:11, Dingyan Li wrote:
  
> In proc_conninfo_ex(), the number of returned bytes is determined by
> the smaller number between sizeof(struct usbdevfs_conninfo_ex) and a
> user specified size. So if we only append new members to the end of
> struct usbdevfs_conninfo_ex, it won't impact the bytes in the beginning.

You have just caused memory corruption in user space by overwriting what
was right behind the buffer of the agreed upon size. Or, not much better,
caused a segmentation fault.

	Regards
		Oliver