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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?EQmlHDaCKC8I7JYciZqL5HZwz3ST6/Xpf7qcvgPhBAEs+hCRr1tOlcyTblY6?= =?us-ascii?Q?9EtP7OwIAv4UH1mrot9rL1TspdlpfsAz4RV2tIRid1oyrzGbW+eGXwxLhYbE?= =?us-ascii?Q?rbFjzO7jNNe7dHy5gMZ/9ke1MMKPpLvUut0hj1w2DcGJ0iLzCwknjNdoz4xo?= =?us-ascii?Q?I57iFlGko1PUW5T6YT+WLCE/aBIkCXfprpHC5+uU4EG4Q5GgY/lbBifN/yZx?= =?us-ascii?Q?bIEXLUPib2rr52X2Yk+1Gk4mMfIct9DQg8dhQVVI96qdk8ySF1+iVJTPhq/N?= =?us-ascii?Q?Bu8o7ZMBQoZiII+boO7RDK4TrVs0EFLPYZJ5CM70yTkQmtf1y6k5vRuBexS/?= =?us-ascii?Q?CF9FyRemh+y5THGlXs6vlMAF29PIGbnuGUL3YN3fD1k7jYKfTuoiEDeFsNTA?= =?us-ascii?Q?pA0Jet5LJoKJCrCzh+lCWTIQCtcIyCvFaoFeuNLaJMXtjZaVOPJUsJjZ0Jok?= =?us-ascii?Q?OTKZh4ZxIh/K01Nhh14qDCMQsQf6BFPWkkBPQmaXLbCaK4JNPDQSfgdVZko8?= =?us-ascii?Q?drW8T0cJrti7sQs7eGDtgx4WYQqJqQPRk9ojI2bnbbgY/8v18w8RslPNJfFc?= =?us-ascii?Q?cAv/+0Cf8YhYclRO4uDPmmdO99LCK16zHIZByGkjUa+X/e2NaeHWp9y52wyX?= =?us-ascii?Q?iw/JgxpD4XWfANWZDI9QsWVtXp3JBfF4ulhgomCoVylMuhLfYt8OEvFfj1fo?= =?us-ascii?Q?GL6g9V50RENCfvUaV8i7nBzihBPCX6ZQil2zsAcmMNohS9JZyRG/eFNHwj1E?= =?us-ascii?Q?wZxqppimqRgAQPs2MWqZ7m9ElkCn99da1XGQSHPG+jOkL0zKS4VHfXDiVobv?= =?us-ascii?Q?BIqGyryXw9kJB5NVhSqZbl3Jrd7stXju2BsJqvtY+DFzG2TSC7mETOSf+Cs5?= =?us-ascii?Q?umatA1ee4qxfSut2tvLYoo6pCkqGJ8LSKnkH+oDTO5kOljOk54eDcq+fU+Qx?= =?us-ascii?Q?6L6L1kTk4BWrFerbyjTcx7AGD3b00O92myAQud/jEhQY1EOO0n0f/GJ1JhZ8?= =?us-ascii?Q?3J0Y59fG2RvuC24KSCH0QPhwLMj/H4slUaRfPcOYGAW6+L9MBUuiPTmlb1pJ?= =?us-ascii?Q?cJmkMHMlNuhpPoz4qL+OlJVWbld9cjX54gii0n+nSepYSjbQdqaz8W4AnGOC?= =?us-ascii?Q?4wttjzYVNdZWqt0TrDW9zkBUSnrWN9Rs9L88JPBHOg2gJaFMYhYyHhn+9CKr?= =?us-ascii?Q?DXsEE/ypUGLtGZByFdQoFO+0fdvuMhrgOsIJ7zP2bkpR/rohcfk3SCpx21kk?= =?us-ascii?Q?MhLPRmb3TXh6VAXxvu/X58JY6BoH21EQVX1UpTkN2l7oWy078SaWbVMemQjW?= =?us-ascii?Q?9oVDwFF/atG59W4Z6LOdIqvowWv0/ipWHp3NNFBowlZBhskoodugu5w3kvQl?= =?us-ascii?Q?4Ho0xscuYtmKf+RQkAFZtoZJt3iWrIGzfnCpVB4J/hI8D5C5Q+NiwnzK8UQ4?= =?us-ascii?Q?jV70bKv33VvfDNX471ZbEBgS+/XHq6ur/LG7GY/EagcT1fdk9duXXGjBdIts?= =?us-ascii?Q?g4mW1L+9omK+X2WTvFvczJH7XtnyP9UM8qTozgku/KpG0Z8k/ZstS6LhXoBp?= =?us-ascii?Q?l90KbU/EJi7JtWYgaSI=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 469a7969-1f4c-488e-9428-08ddd5013c49 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Aug 2025 15:52:24.0947 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: ceU57TWDPIJFxqwhTHdi/U3tEFODzBIKFoOR5oE1qiwPTWu+EUrDwkfquL02tqd1 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR12MB7243 On Wed, Aug 06, 2025 at 08:03:42AM -0700, Dave Hansen wrote: > Hold on a sec, though. the problematic caller of this looks something > like this (logically): > > pmd_free_pte_page() > { > pte = pmd_page_vaddr(*pmd); > pmd_clear(pmd); > flush_tlb_kernel_range(...); // does schedule_work() > pte_free_kernel(pte); > } > > It _immediately_ frees the PTE page. The schedule_work() work will > probably happen sometime after the page is freed. > > Isn't that still a use-after-free? It's for some arbitrary amount of > time and better than before but it's still a use-after-free. Yes it is. You can't do this approach without also pushing the pages to freed on a list and defering the free till the work. This is broadly what the normal mm user flow is doing.. Jason