CVE-2026-43303
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| rhel | 9 | fixed | |
| debian | bookworm | affected | |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.19.6-1 |
| debian | sid | fixed | 6.19.6-1 |
| debian | trixie | affected | |
| linux-kernel | affected | 6.18.16 | |
| linux-kernel | 5.18 | affected | |
| windows | affected | |
References
- https://git.kernel.org/stable/c/23b82b7a26182ad840ae67d390d7ec9771e8c00f
- https://git.kernel.org/stable/c/ac1ea219590c09572ed5992dc233bbf7bb70fef9
- https://git.kernel.org/stable/c/d757c793853ec5483eb41ec2942c300b8fa720fb
- https://www.suse.com/security/cve/CVE-2026-43303.html
- https://security-tracker.debian.org/tracker/CVE-2026-43303
- https://access.redhat.com/errata/RHSA-2026:21556
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43303
CWEs
CWE-416
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.