Bug 2532513 (CVE-2026-89500) - CVE-2026-89500 kernel: ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page
Summary: CVE-2026-89500 kernel: ring-buffer: Make cpu_buffer::free_page a buffer_data_...
Keywords:
Status: NEW
Alias: CVE-2026-89500
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-11 23:35 UTC by OSIDB Bzimport
Modified: 2026-09-15 06:59 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-09-11 23:35:19 UTC
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.


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