CVE-2026-43303
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: clear page->private in free_pages_prepare() Several subsystems (slub, shmem, ttm, etc.) use page->private but don't clear it before freeing pages. When these pages are later allocated as high-order pages and split via split_page(), tail pages retain stale page->private values. This causes a use-after-free in the swap subsystem. The swap code uses page->private to track swap count continuations, assuming freshly allocated pages have page->private == 0. When stale values are present, swap_count_continued() incorrectly assumes the continuation list is valid and iterates over uninitialized page->lru containing LIST_POISON values, causing a crash: KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107] RIP: 0010:__do_sys_swapoff+0x1151/0x1860 Fix this by clearing page->private in free_pages_prepare(), ensuring all freed pages have clean state regardless of previous use.
Severity
HIGH
CVSS score
7.8
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-08 14:16:37.583000
Last modified
2026-10-19 20:18:13.083000
View original CVE JSON
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"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-05-08T14:16:37.583",
"lastModified": "2026-10-19T20:18:13.083",
"vulnStatus": "Modified",
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_alloc: clear page->private in free_pages_prepare()\n\nSeveral subsystems (slub, shmem, ttm, etc.) use page->private but don't\nclear it before freeing pages. When these pages are later allocated as\nhigh-order pages and split via split_page(), tail pages retain stale\npage->private values.\n\nThis causes a use-after-free in the swap subsystem. The swap code uses\npage->private to track swap count continuations, assuming freshly\nallocated pages have page->private == 0. When stale values are present,\nswap_count_continued() incorrectly assumes the continuation list is valid\nand iterates over uninitialized page->lru containing LIST_POISON values,\ncausing a crash:\n\n KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]\n RIP: 0010:__do_sys_swapoff+0x1151/0x1860\n\nFix this by clearing page->private in free_pages_prepare(), ensuring all\nfreed pages have clean state regardless of previous use."
}
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