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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?wktDGgGxU7MMVMIb1Br7bADPuDc7Em0O9+jpCeIcm7tUUoy0wgjUJeYcE9MT?= =?us-ascii?Q?teGRfPeL22fx+QjqwdGPOclV8h+Lb5w96Yw+iX8GFBBibo3XwsM8qLzkiOF4?= =?us-ascii?Q?Xhc8vapH+U3c0W3ALJkzFi/IEuQ1JaQNb27dvyLoHUHcI+zrFnjO+Vdmm0rS?= =?us-ascii?Q?xrJu7i99sXp30PacikmrQfjfMbK0c0SgRs5RQmgmGF1QFIpBifSgNnGKeZQ2?= =?us-ascii?Q?KgXPQMnU22WppzsiVKTzrqQjhtZL2NMaLmIzmvA6GmdLimT4fQoHiacdOv4I?= =?us-ascii?Q?wqBMykYsxs6VRGCTB9tPs9RPI2D6hZ99IeLBE9BtCt47jkVsORbq1nftXTmA?= =?us-ascii?Q?UXXoy6QevCp+g7CXW10vN7V7hQWCYubkjrI7oO7ZoIYFsvSA0LcKWBQwxjQx?= =?us-ascii?Q?By8aKnfEfuHbCdmoQz4zO4ZOsCZCjJAnPvWjHpedULSVBs8xX/SpWJmtsRXl?= =?us-ascii?Q?4zMyyMsIshMmL5HWQETNLYgSv46Y4OxwGdwvKNFa2dwvpDFlSzX1SMsu2ky0?= =?us-ascii?Q?TV5+2InjBJaCA0CA1n/Viibmu0J48vbFApnKI3lw9dEspJCTg3zRaACP/yXJ?= =?us-ascii?Q?npGXMx/BbtqSPRxrsYHM1PRHPEF99hTihOUExWaEzNUnTl9AF72B3BRyIT1a?= =?us-ascii?Q?GexobLm3DQWA5sHu86VwRKSx52C/+eF300VXLfkLkGN4quxqDx3zHIITBlUb?= =?us-ascii?Q?52qiexQY19+1SkCQ7LcThgNdrswNqs8dhPRahkluaJZtrD9j7tOKrqgrKM4t?= =?us-ascii?Q?GYZVkPceWkEpN1b5M/4weGwKZHYrjQncQ5PZ84HXl6Tt/cfrvU6wDzPNIeWg?= =?us-ascii?Q?GIgiMX02ZlmyzRaUqRZaC4G2U17BC6BM3BF7IH1qyXyYvL+s0yO8o7hiNHrB?= =?us-ascii?Q?eYCWmQ/oHw+Ncb6W//tpaJOB2zFIJL3maMNuJhZIFdlC6LoiqIBefPImruNj?= =?us-ascii?Q?Uj4j5mmKumokdcVUYPjh0g0arK+2/8v+r+n9L4ezZvt5MSOrcdbWU+clBwOr?= =?us-ascii?Q?fNh5IQJC9mjB8Nbv621FV9dfSrZSobwLl9QEFIC/xPU4d/xtqTq2QKDMKBS/?= =?us-ascii?Q?O0zs5CE0baICut6LvZeZxB0rhXHywQCVkfePxfbtZpAOhiDnwi1Yr8Uf7iKT?= =?us-ascii?Q?Qjq/wfINWW23JgxbGBwBBg7A/kQjlRk46L3u8LXVIz9FZbsZ+fNZsv4PIySb?= =?us-ascii?Q?PA/RfrASNQElT8LGymWF4+JD7VA6HjBdhQgtp/hO/5B+WtKT2kEjZiHmNrKb?= =?us-ascii?Q?6mbKqjDJTK0IQCxWvhucJWI6lVsWtvfh0RQLcVmVTYpZvXgcpJtjZK4PchDn?= =?us-ascii?Q?iiKpnQx87RkKLkKkVdkDy9XNuh451jJ/TzcdThURK+UVad6v+uL1ausR4GJu?= =?us-ascii?Q?NH+YIlvok0vnsFqnLdc3icbhIDEJerep/kEuDOF2/pC28YAg7lq8TiCb7GY5?= =?us-ascii?Q?QXIHu7P7zRGlur1mS4R7B3zPnpUeBZvOrZ2xh03ID4X2cPhdlvz7G4yljwHw?= =?us-ascii?Q?7jDWXHy5pMtoyjQ8pLE3cNSZgCzS35V7SVxLi8FUmRrIDPCrg0SjN8CDFVA1?= =?us-ascii?Q?DQahvMWwSMnr4YBEe9uctloocaBxUoC35asN6d52+u7+Y8m/Sz8aC2ZIYfzQ?= =?us-ascii?Q?dw=3D=3D?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 072a0247-175d-4a0e-8f50-08db32cb577b X-MS-Exchange-CrossTenant-AuthSource: AM0PR04MB6452.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Apr 2023 16:08:33.2694 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: K3mlLJQp2PrithrmuTyOJzH8oqGGuQDO3+hGZznMm1B227GjIc17vSWkGHUq5wqry4cpq3T/FQ2Mp7nU1dgdSw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS1PR04MB9504 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Mar 30, 2023 at 10:35:19PM -0700, Jakub Kicinski wrote: > > case SIOCSHWTSTAMP: > > err = net_hwtstamp_validate(ifr); > > if (err) > > return err; > > - fallthrough; > > + return dev_hwtstamp(dev, ifr, cmd); > > Let's refactor this differently, we need net_hwtstamp_validate() > to run on the same in-kernel copy as we'll send down to the driver. > If we copy_from_user() twice we may validate a different thing > than the driver will end up seeing (ToCToU). I'm not sure I understand this. Since net_hwtstamp_validate() already contains a copy_from_user() call, don't we already call copy_to_user() twice (the second time being in all SIOCSHWTSTAMP handlers from drivers)? Perhaps I don't understand what is it that can change the contents of the ifreq structure, which would make this a potential issue for ndo_hwtstamp_set() that isn't an issue for ndo_eth_ioctl()...