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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?v+ssguYM1DA3lsOxuKft6ajVbw3zi0tr3Ji2KMF8FTdeDL6pYwstsTa8SAfe?= =?us-ascii?Q?dw2yEUdqZ+07TpUE34TVK7U34K/mF7PXOKYmtPt1ajLP17AiGsUl5D2+/9lR?= =?us-ascii?Q?r6DhTbQwPXAdlwKP/lrAa1GguoPQtF6wdZPbWGaS7f4o8zgdxyUx1SNILygR?= =?us-ascii?Q?MVQztiujRU8c1n8E9BY2cPo+UAQIgG7Jhov68MGYg4BZBeN4e25RN62nrbge?= =?us-ascii?Q?NSxHR4hTShNDOkCgy4SwYUewJHMgeOytyIarh3N07PjkdZHtOIskqzGo5Dsq?= =?us-ascii?Q?2WbUMcgO4+33hh5eSXsdJcJ8Gy0q/GCznqSpfvZ/86FjU6Psq3RDJPn8mKD6?= =?us-ascii?Q?rmh4066xORjVCPDEDJKuiL5gqxrie+e4//1VtfnOtikiu28A3634k/jCv4FZ?= =?us-ascii?Q?Ha7b5o6jOvDnhAoQtZ74XDO5ExJbAFK+4dbzZxAfdUA+Qtt82Kj1C1AoSjNh?= =?us-ascii?Q?AfmFbF5marX/pXYdtk/rCNEtNJpLhsHTuGaC7PZI9bsKxWA0J44wSy39Zb+D?= =?us-ascii?Q?5Tik5XVTvJjzbxUB4+WA4WH2R7Xdu9Sz/GXQHvbqso4uUH/UlpMiiNdChvN/?= =?us-ascii?Q?yRCKVu+bYBv7rpxCdJEuVFXC/GigvSBpUMgzK06YNLgEeEA6XDLMSnHmjDX3?= =?us-ascii?Q?yWtgFt4fX9oAICTwoOmn2PqFMw1/LQ1idMeK9XnGxM/SsuRm2BF82vKH1iUL?= =?us-ascii?Q?NKiTqa5bJf3vJU+3uN6bepRwVZawOei7JAgcDvNQGSGwWhraq65TGsbK2xYN?= =?us-ascii?Q?rYrKoeq+CLo00qAjMw/t4YhPOjfoKRQivy0g0cp0dm/xeN3yTbEURgTUTzP0?= =?us-ascii?Q?gLtTwuzlSsvDtFoOK4mo0E7kPGfgiCxU3OnKI3HvwNhTCPuGjQ7ppXu7NVs3?= =?us-ascii?Q?qe3F19ONXSUKYZfA97gDbxeWWO7XBwMD5EJOts7px8XGVYu11sYSIc6FGeg7?= =?us-ascii?Q?JL38apfdnniTRd71GisYew/iJKf00/5zreH1PUtbadX+LD1gPyj0c062noFt?= =?us-ascii?Q?A79XoKMeB+pbSwHJclFAkpYqPzMlsKnmIV1z+jM+wiP7+astcu+hxwvrhm8d?= =?us-ascii?Q?PXIABQ1m7UkydYsI2cFxiIvsP+MYQXkFXz6Rl+aiyxGNQJ0jXOz6UkkOYo5K?= =?us-ascii?Q?ZiMcJnMlEKmr7BCsXj12h2YHMHqwTomAbtfu47YC43HaPwTtBPbun57afoYt?= =?us-ascii?Q?Ky/Yujp1x3IuBR74zRuBy8aXVrz998wV9CAGoubeyT4p/AxP/1qnZjOeuba0?= =?us-ascii?Q?lcoe36ULVDDRZkPuZ18Z8t7j22iJDpNVLRBEAj3D6FY8bf2cC1C+w1Nc7vyG?= =?us-ascii?Q?aZ0pOWiR8jWo0EQUehgGJwxrM8k5CJ88nEJ+zwozf2474rIPIBR0VNthYx1r?= =?us-ascii?Q?lFuSatR7KdJkhtW3otsGnsInyyD/e415/maOHgy+3apFzXlJHWuJ+fhfusMy?= =?us-ascii?Q?Pf3ZQlZYSZx1iUZNJSQv5anFcRXJINWdC7F2SURYPRFtIys4W5FEC0NPWxnY?= =?us-ascii?Q?RN2yHLn1zCwj/7dTUFfeWRk1suRsKPdJ+gpW7XHAo31/iAdN89t9ZiIYXn9w?= =?us-ascii?Q?iG5hvCjU6CQtaeJg0VzIcttWgg1O7nJvLjgU4R8kjTWi6vh9f6y8NJ+GReqA?= =?us-ascii?Q?554RJlS3WACPy5oTrEPNzKEsyytTepKNG1p0AXmyq291I5JeMJ1IDVsz6VlH?= =?us-ascii?Q?Olm7XM4JKDPC9fiZVdALnxH2B50YAZ3yeS29dBUvK09Q3vy9a1ALGGP9Hccq?= =?us-ascii?Q?mGxnFbUANw=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: b7c6c419-16e0-4a01-6bf3-08dee0904768 X-MS-Exchange-CrossTenant-AuthSource: CH2PR12MB5001.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jul 2026 03:39:01.3071 (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: eYT7IWLpWLkIaPYw1woROCil7jvMwIR8iyU4cDHDXh02/hQiyygcneNlw65GdO8nhPGREiKuJGYbgW/4SCgbJA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB6327 On Fri, Jul 10, 2026 at 03:55:21AM -0700, Usama Arif wrote: > queue_folios_pmd() is called under pmd_trans_huge_lock(), whose > pmd_is_huge() check returns true for any non-present, non-none PMD > softleaf. Passing such a PMD to pmd_folio() treats the softleaf encoding > as a hardware PFN and can return a bogus folio pointer. > > Mirror queue_folios_pte_range(): handle non-present entries before > looking up a folio. Keep migration entries counted as failures, but skip > other non-present PMDs such as device-private entries. > > Potential trigger: an HMM-based GPU driver migrates an anonymous THP > folio to device memory via migrate_vma_pages(), leaving a device-private > PMD. Userspace then calls mbind(), migrate_pages() or > set_mempolicy_home_node() on that range. > > Reported-by: sashiko-bot > Link: https://sashiko.dev/#/patchset/20260703173903.3789516-1-usama.arif%40linux.dev?part=6 > Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations") > Cc: > Reviewed-by: Joshua Hahn > Reviewed-by: Zi Yan > Acked-by: David Hildenbrand (Arm) > Signed-off-by: Usama Arif > --- > mm/mempolicy.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 914f81863db5..69a00a324ef5 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -654,12 +654,14 @@ static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk) > { > struct folio *folio; > struct queue_pages *qp = walk->private; > + pmd_t pmdval = pmdp_get(pmd); > > - if (unlikely(pmd_is_migration_entry(*pmd))) { > - qp->nr_failed++; > + if (unlikely(!pmd_present(pmdval))) { > + if (pmd_is_migration_entry(pmdval)) > + qp->nr_failed++; > return; > } > - folio = pmd_folio(*pmd); > + folio = pmd_folio(pmdval); > if (is_huge_zero_folio(folio)) { > walk->action = ACTION_CONTINUE; > return; > -- Reviewed-by: Balbir Singh