CVE-2026-31644
Description
In the Linux kernel, the following vulnerability has been resolved: net: lan966x: fix use-after-free and leak in lan966x_fdma_reload() When lan966x_fdma_reload() fails to allocate new RX buffers, the restore path restarts DMA using old descriptors whose pages were already freed via lan966x_fdma_rx_free_pages(). Since page_pool_put_full_page() can release pages back to the buddy allocator, the hardware may DMA into memory now owned by other kernel subsystems. Additionally, on the restore path, the newly created page pool (if allocation partially succeeded) is overwritten without being destroyed, leaking it. Fix both issues by deferring the release of old pages until after the new allocation succeeds. Save the old page array before the allocation so old pages can be freed on the success path. On the failure path, the old descriptors, pages and page pool are all still valid, making the restore safe. Also ensure the restore path re-enables NAPI and wakes the netdev, matching the success path.
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 | | |
| debian | bookworm | fixed | 0 |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.19.13-1 |
| debian | sid | fixed | 6.19.13-1 |
| debian | trixie | fixed | 6.12.85-1 |
| linux-kernel | affected | 6.12.82 | |
| linux-kernel | 6.12 | affected | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/59c3d55a946cacdb4181600723c20ac4f4c20c84
- https://git.kernel.org/stable/c/691082c0b93c13a5e068c0905f673060bddc204e
- https://git.kernel.org/stable/c/92a673019943770930e2a8bfd52e1aad47a1fc1f
- https://git.kernel.org/stable/c/9950e9199b3dfdfbde0b8d96ba947d7b11243801
- https://www.suse.com/security/cve/CVE-2026-31644.html
- https://security-tracker.debian.org/tracker/CVE-2026-31644
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.