Copyright © 2012 Red Hat, Inc. All rights reserved. Low 2026-09-11T00:00:00 kernel: net: phylink: correctly validate returned PCS in phylink_inband_caps 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-476

In the Linux kernel, the following vulnerability has been resolved: net: phylink: correctly validate returned PCS in phylink_inband_caps In phylink_inband_caps(), the PCS returned by mac_select_pcs is only checked if NULL but mac_select_pcs can also return an error pointer. This can cause a kernel panic as phylink_pcs_inband_caps() only checks if passed PCS is not NULL and directly dereference ops from the phylink_pcs struct. Use the IS_ERR_OR_NULL macro to address both case where the returned PCS can be NULL or an error pointer and prevent a kernel panic.

A flaw was found in the Linux kernel's `net: phylink` component. The `phylink_inband_caps()` function does not correctly validate the return value from `mac_select_pcs`, which can return an error pointer instead of a valid Physical Coding Sublayer (PCS) object. This oversight can lead to dereferencing an invalid pointer, causing a kernel panic. A kernel panic results in a system crash, leading to a Denial of Service (DoS).

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 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt Red Hat OpenShift Container Platform 4 Not affected openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Fix deferred openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-80993 https://nvd.nist.gov/vuln/detail/CVE-2026-80993 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80993.mbox