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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?iXJH+0hWCxScNzNFDahJgfcf01TYgU/7JTxivzD3D1KWwJoCsoZsvN2l/4we?= =?us-ascii?Q?FLhJEol8RKAZ9heBmyHEp7Jdq4AIbQSu4lAl+HXA7Tm6gCX0yclRHa6eMsHP?= =?us-ascii?Q?/lUXILCE2fqypDf2ZzeY9N8BZjaIX7qWW4+RTHZz8Oir75Y/ObuWF0RfuhNe?= =?us-ascii?Q?6h582MdhXHgpyN4TuBsul9WZQw9QvZEOXwm9AzYRvXCGqzD9c/17YiDWymdC?= =?us-ascii?Q?aLSpaGybv4brCb1irr6TjwrXLsvNMWn1BlbV6G3LOFLCn99oVmB53JkSdF04?= =?us-ascii?Q?9JN68WbNEgnnl2OCW/LkCU0u9wCR1ZhI5TBdUFLxqyMxh4GFiU3GmV7a5FDx?= =?us-ascii?Q?JKO5S2VPo2YOPjYHy9U1i3Oxwn6IM6WbxjNWnIWPRu7T0MSPXTwrqFjpZ08S?= =?us-ascii?Q?NbH3vNeV/UN3yZAwNISIS/edSRX7xeeGLUIGraVPeK20nGG7RBvYyHGc2hvi?= =?us-ascii?Q?N+w08+lUjAANePZAtHyu5XUbQuLlLjtyXakMWihkBwvPriTYVpuEWqpKyCUF?= =?us-ascii?Q?nh+t4pK15GazqTPQF5scCKPcq5D/SC/tTWNH6PuDEsfy9zHlQxlE8kIcXele?= =?us-ascii?Q?CDaJxSo4l3WdQhEQAfaiF6KXMwBTV9T7m0ls4sRfCmQY7BIJbt6Nvmm8EyoL?= =?us-ascii?Q?kHyclWIoGAZoVg9Y6SL4IB3+UJNWBEWQpJz0Mzw9zHgPF5Oybss/lNhNgyGw?= =?us-ascii?Q?XvjTkYbjfCWB3pFxUF7pUw7wad1GV7JIn04z9gTh3N+feDen2n/MgeiYD/mL?= =?us-ascii?Q?M/wcWTIXkLmx/dRBtEVl5eFNUY6PtKpkdA3K8AhAHigtbcC8GpdT7X5DA9bn?= =?us-ascii?Q?opEBhXn4iybqOLx7aYvgSnhJ+Vo/USkYKydo8JSMgaORLFR0x6M9zRtowKmL?= =?us-ascii?Q?7tlhWUfvCBHJIQgalLmOWVov5fJ7p4yQ5HVS0Zxl25n5G4O2Q+kLPi8vg9Lv?= =?us-ascii?Q?9wwXDvlNrwh9KEn2jvH10LL/6882bbMjO579FuLmeOfTQLyJb67ebq/cJIIE?= =?us-ascii?Q?MQTAZifv6zdP+t+R6wV4g+qFSOvMbTeoGY5YkwjGPA5I4pkAW2og5q8dpoTp?= =?us-ascii?Q?/5OSom8lZd9AE0ZwyTjg8B83yUTwHcSCV5cyH1zxBROko/oH6lat69unU+he?= =?us-ascii?Q?vMH62/Ou4+Ztkas1m2TzmXZ2snQkv5FUOj2WqLRcvE9lvsNp5X9sbTdkFaZs?= =?us-ascii?Q?JxsnAvRXXMmvV0PZ7vXpBomHWQxuNRao5ZLL6J+OawhUi8NkinGkeAIMbYjM?= =?us-ascii?Q?8F6PL9SGo8JohLKc967Rhk8E3CJwLAU4JXPSZ5t5uj3XgZnociKoi2B5uKrl?= =?us-ascii?Q?i5H7RgDNaga+885fMPR/vhoULGHGl5slNbWOT517YQ0IE/HHcdaOMl/3rk2o?= =?us-ascii?Q?Ucgi2xAwoRZ+AMeyjKpx7YQRlYSMARiZYmiOFTbJQ0A24QIpYaTybV1KhQwW?= =?us-ascii?Q?8f5MNEfgRyXvZ90Q3Wm8PmHjeMMKRvQ8ntK9tj21wfXKj+ehF4Og3uj+ht1s?= =?us-ascii?Q?LeDvt6OuYbr846lQ1rJjnTq8lx3Fv2TTX/HcHNC3Nn7y1VaGapNznDiYZHXp?= =?us-ascii?Q?wxfJmNt+O18YbOP3JadY7D+h2QYdtU6La5RgZ2ZQ?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5b5fd8a3-04bd-4a25-e400-08dd193629e0 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Dec 2024 16:17:37.9027 (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: M0sUzS4Ma8P59opKAn5tZNhaMafi3oefC+Uk042uEi6F5uBYB0AYXCYdtrQR6H27 X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV2PR12MB5917 On 10 Dec 2024, at 4:34, David Hildenbrand wrote: > In split_large_buddy(), we might call pfn_to_page() on a PFN that might > not exist. In corner cases, such as when freeing the highest pageblock in > the last memory section, this could result with CONFIG_SPARSEMEM && > !CONFIG_SPARSEMEM_EXTREME in __pfn_to_section() returning NULL and > and __section_mem_map_addr() dereferencing that NULL pointer. > > Let's fix it, and avoid doing a pfn_to_page() call for the first > iteration, where we already have the page. > > So far this was found by code inspection, but let's just CC stable as > the fix is easy. > > Fixes: fd919a85cd55 ("mm: page_isolation: prepare for hygienic freelists") > Reported-by: Vlastimil Babka > Closes: https://lkml.kernel.org/r/e1a898ba-a717-4d20-9144-29df1a6c8813@suse.cz > Cc: Andrew Morton > Cc: Johannes Weiner > Cc: Zi Yan > Cc: Yu Zhao > Cc: > Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Best Regards, Yan, Zi