CVE-2026-43303

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.