CVE-2026-89500: Linux

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page Discarding a cached reader page after a concurrent ring buffer resize uses the new global subbuf_order for the free_pages() call. This mismatched order may crashes the kernel or leaks memory because the cached page was allocated under the old size. Save the actual free_page order alongside the page address to ensure we always refer to the correct value and do not rely on the potentially stalled cpu_buffer->subbuf_order value. The simplest is to make free_page a buffer_data_read_page which already covers exactly what we need: a page address and a page order.

Affected products

• Linux Linux: from 6.8, before 6.12.112 (fixed in 6.12.112); from 6.13, before 6.18.51 (fixed in 6.18.51); from 6.19, before 7.2.4 (fixed in 7.2.4)

Published 2026-09-11. Last modified 2026-10-03.