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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | HIGH |
| Integrity Impact | HIGH |
| Availability Impact | HIGH |
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Type: Secondary
Exploitability Score: 1.8
Impact Score: 5.9
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-416
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23549fc480> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24243df000> | Operating System |
| linux | linux_kernel | 5.18 | <built-in method update of dict object at 0x7d2364d6a600> | Operating System |
| linux | linux_kernel | 5.18 | <built-in method update of dict object at 0x7d24245bb600> | Operating System |
| linux | linux_kernel | 5.18 | <built-in method update of dict object at 0x7d23549fff00> | Operating System |
| linux | linux_kernel | 5.18 | <built-in method update of dict object at 0x7d24243df400> | Operating System |
| linux | linux_kernel | 5.18 | <built-in method update of dict object at 0x7d24245b9680> | Operating System |
| linux | linux_kernel | 5.18 | <built-in method update of dict object at 0x7d24245bb0c0> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:5.18:-:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:5.18:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:5.18:rc5:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:5.18:rc6:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:5.18:rc7:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:5.18:rc9:*:*:*:*:*:* |