CVE-2026-31644

About vulnerability

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. A flaw was found in the Linux kernel’s lan966x network driver. When the lan966x_fdma_reload() function encounters an error during the allocation of new receive (RX) buffers, it can lead to a use-after-free condition. This occurs because the system may attempt to restart Direct Memory Access (DMA) operations using memory pages that have already been released. Consequently, the hardware might write data into memory regions that are now allocated to other kernel components, potentially causing memory corruption. This could enable a local attacker to achieve privilege escalation or trigger a system crash (Denial of Service).

Live-patch status from KernelCare for each operating system.