Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-09-11T00:00:00 kernel: ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page() 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-367

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page() ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set, it can allocate a reader page with an outdated order. This isn't a big issue, the user can still re-allocate a new reader page and try again. However, what is more problematic is if the value of subbuf_order changes in the middle of ring_buffer_alloc_read_page(). In that case, bpage->order might not match the actual allocated memory. Use bpage->order for the allocation to prevent this race.

A flaw was found in the Linux kernel's ring-buffer component. A race condition exists in the `ring_buffer_alloc_read_page()` function when it interacts with `ring_buffer_subbuf_order_set`. This can lead to an incorrect memory allocation where the buffer page's order (`bpage->order`) does not match the actual allocated memory. This mismatch could potentially cause system instability or a denial of service.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 10 Fix deferred kernel-rt Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt Red Hat OpenShift Container Platform 4 Not affected openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Not affected openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-89503 https://nvd.nist.gov/vuln/detail/CVE-2026-89503 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89503.mbox