CVE-2026-43303
7.8
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability: 1.8 / Impact: 5.9
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)
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.
Affected (8)
Products: Linux: Linux Kernel
Configuration A
| Vulnerable Software | Affected Versions |
|---|---|
| 5.18.1 ≤ version < 6.18.16 |
Related CWEs
CWE-416
Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
CWE-457
Use of Uninitialized Variable
The code uses a variable that has not been initialized, leading to unpredictable or unintended results.
References (9)
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Timeline
No history available yet.