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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?v6IPK3nu54BPkjxIWPWxXLBG0xRHNr8cMHDr0yXIGWXPKbZmHm0pTi9MoPi0?= =?us-ascii?Q?pxtLdkbPgzAwTTRvTrl7y7mXkPqAbPvrYg+hWqNm21OD0tcDXdk1/fRAXoIO?= =?us-ascii?Q?yxtcG2Zo/TlmkXAB6LxfXOeAuuZemHEC0RejFXq0qRqrtFATd25dx7uy6oAt?= =?us-ascii?Q?3YdSesjqtHxpxQ1j7oYOCjnYubKCJmVLxZcK7/7G2+HRFDZaTXqmno5YQTiK?= =?us-ascii?Q?1Wl6eNdJnzE5rOtfZlQJTKSRhmN2Umt/YRWTmUnh439neCMI1vtPcvfELoKs?= =?us-ascii?Q?hHM8J83DoHIWnrqn91O4uzq36jBN6GaVlG43L1fZ4w40xW48e/mw/vP3DSp3?= =?us-ascii?Q?IPhqX9OK0GnTW52HMFLzLaKhSrQNImmc8RpTwZBqwqkpeNo7Hq42hYZy+k0Y?= =?us-ascii?Q?T5EBrVjCDB+LWeE8aV79TRho1tKwq5HAwmR7cKpMbTmQLYZQstf1L5IDVB7Z?= =?us-ascii?Q?Wk2IlzGC8VytEfuUe4hYUy9Gi77bZFS9nhgjXgv+F9WBg6CSNrgtenzu7Iaf?= =?us-ascii?Q?H+OIwqhES8jFRRXrBt5vvWjMoO5/wzBlwKuZJIaTb8S/SFx/+YDGWucQG/Qb?= =?us-ascii?Q?8bxRBO+8Q8mF/zvrZ80xghKjvZuf622vxyNLsGT2X84x6gNbF2tweDg0yMxW?= =?us-ascii?Q?udwVpcJ2JXuFcct7imFw333SXaoHkxPZ5LISoaTyCsMJ/mg310pkR4ZxES5Y?= =?us-ascii?Q?MV17HmtJ49v71SkohliiMi1TZ4JmfrWIk7REW73SpqmsqpKdceNGK2jl0+bA?= =?us-ascii?Q?bJ9CFkIXjdK9OwJgbZW7/zogug5BrB29NpI16DPmdfvgZVplvR5vxv1WaJgp?= =?us-ascii?Q?GaObvZcFcBuYAEtYmXWy3LYoeIKDB6M/37Oq57vPSbuCB6Ki24CoeXyNVFer?= =?us-ascii?Q?6cD9cJZp0cZXl69vKIkSwHATikho+xuql+kstZQ35DXs2t/JV5Mlg1NODK6i?= =?us-ascii?Q?5KWQFrAfWjoB5av6HzyvVjAPZqZxMYhwTNJWa9VK4CqHxuAdCSWbET0fa6N2?= =?us-ascii?Q?NCFRRF1SnAMulVbIDVJ2HLUR40DjW9OqZEc3uHWT6rVxJsvRZfCnV5DV4uj4?= =?us-ascii?Q?cXWwjJpR4FGTnua0jgrDxMElWckGLh4J5opSM1lKxiFPpbqOh96A/Y5AcWTi?= =?us-ascii?Q?6y94H72qMW9FM/tZCITYWb0Qf2qxKKwob349Jja/2UbRIAFEnTJVYJ7smUhf?= =?us-ascii?Q?SYKMGFyboZ+Umik1VXXbT855yhdwbsANsq4NdOifRqsw/y41eLxbM6dz/osU?= =?us-ascii?Q?Buu37vZuBvDo8osgJDUeN+FGl2i99alvQRB7UTTZBOMAbNbgK3hWmgqj4Low?= =?us-ascii?Q?Zz8ckdNoHOEhy1q7wMAakto+Qk5PXwiLPGyYhoX4tOpgUWirxU62sVZXNPlK?= =?us-ascii?Q?XrORMGRSXzYJAhwBmyHiU+N6Nx/KsLAMatFtBGz7eAXQSWpyp/zKp5GX/7a4?= =?us-ascii?Q?mFhrM19l+GyP1DoD+Tg7knV9ooI905puNXDO7Azc6gH3eHcyhuKz13Oce3Rt?= =?us-ascii?Q?MQn9El11kHKhAdvtWS5eGd7gokpj3AXGdr/1pzjZ1pzW0wCm20sCCGa9vOLJ?= =?us-ascii?Q?DSR7a0rQrtO9yzwWqVT+ACJsroPQd9Ow5Zaiv3Z6ERC51ZuT8L3jpkvAsoEB?= =?us-ascii?Q?BU9u9iNEqcYEUyovrdLZCk57p2iGUnE4f1OztCYrBP32QG9Yw9TGhSFRkncw?= =?us-ascii?Q?VAgnybozQYWbgu+xoMkb6kPMYhacvrJ6p3eqe4aqv2ECgJd/kZu6CfBAiDR1?= =?us-ascii?Q?wdkvqsPciA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 30152ec0-316e-4085-403e-08df2ac913e9 X-MS-Exchange-CrossTenant-AuthSource: PH0PR12MB7957.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Oct 2026 14:32:02.1932 (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: P0iViBBk0sWPpGg/myWe/neJ4GHsXsMzONAWp+cqSrcpFaumyTw9nPUHRy9mK9eTLRkUagpaZR8QNJND4Vgm0g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB6885 On Thu, Oct 15, 2026 at 02:06:48PM +0900, Daehyeon Ko wrote: > addrconf_ifdown() clears the address hash before snapshotting the > per-device address list. A concurrent ipv6_add_addr() can publish an > address after the hash scan and before the list snapshot. > > The ifdown path then removes the address from the device list and drops > the list-owned reference while it is still linked in the hash. Once the > remaining references are released, inet6_ifa_finish_destroy() warns, but > a DEAD address continues to kfree_rcu(). The hash therefore points to > freed memory that later RCU walkers can dereference. > > This follow-on was found by source review and was not separately > triggered at runtime. > > Remove each non-kept address from the hash immediately before removing > it from the per-device list. Keeping it hashed through the delete > notification blocks same-address publication until NETDEV_DOWN has been > delivered. hlist_del_init_rcu() is safe when the earlier hash scan > already removed the address. > > This handles a late publisher captured by the list snapshot. The next > change serializes publication with teardown so an add cannot miss both > observations. Both changes are required when backporting the complete fix. > > Fixes: 73a8bd74e261 ("ipv6: Revert 'administrative down' address handling changes.") > Cc: stable@vger.kernel.org > Reported-by: Ido Schimmel > Link: https://lore.kernel.org/r/20261004135117.GA206930@shredder > Link: https://lore.kernel.org/r/179161099539.434549.2238120015372268173@kernel.org > Suggested-by: Ido Schimmel > Assisted-by: LLM > Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Reviewed-by: Ido Schimmel