CVE-2026-43303

HIGH

mm/page_alloc: clear page->private in free_pages_prepare()

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 7.8
EPSS 0.0001
EPSS Percentile 2.3%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-416
Status published
Products (10)
Linux/Linux < 5.18
Linux/Linux 3b8000ae185cb068adbda5f966a3835053c85fd4 - 23b82b7a26182ad840ae67d390d7ec9771e8c00f
Linux/Linux 3b8000ae185cb068adbda5f966a3835053c85fd4 - ac1ea219590c09572ed5992dc233bbf7bb70fef9
Linux/Linux 3b8000ae185cb068adbda5f966a3835053c85fd4 - d757c793853ec5483eb41ec2942c300b8fa720fb
Linux/Linux 5.18
Linux/Linux 6.18.16 - 6.18.*
Linux/Linux 6.19.6 - 6.19.*
Linux/Linux 7.0
linux/linux_kernel 5.18 (6 CPE variants)
linux/linux_kernel 5.18.1 - 6.18.16
Published May 08, 2026
Tracked Since May 08, 2026