Medium [CVE-2026-89503] Linux kernel ring-buffer: Denial of Service due to subbuffer resize race condition
This medium-severity Red Hat Linux advisory covers CVE-2026-89503 affecting Red Hat OpenShift Container Platform 4.
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Summary
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 severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-367.
Affected Red Hat products: Red Hat OpenShift Container Platform 4. Red Hat does not currently list a fixing RHSA for this CVE.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 18 minutes ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 18 minutes ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 18 minutes ago·verify at source
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