Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-10-18T00:00:00 kernel: ip_gre: Reject enabling collect metadata through changelink 4.4 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H CWE-694

In the Linux kernel, the following vulnerability has been resolved: ip_gre: Reject enabling collect metadata through changelink ipgre_netlink_parms() can enable collect_md on an existing GRE, GRETAP or ERSPAN device. Unlike newlink, changelink does not enforce metadata tunnel uniqueness. Converting a non-metadata device can therefore replace the metadata receive entry for another device of the same type in the same netns. Deleting either device then clears the shared entry, breaking metadata receive lookup for the surviving device. If parameter validation fails after collect_md is set, deleting the modified device can also clear an entry it never owned. Reject enabling metadata mode in both changelink callbacks before any encapsulation or tunnel parameters are modified. Allow requests that repeat the metadata attribute on an existing metadata device.

A flaw was found in the Linux kernel's Generic Routing Encapsulation (GRE) subsystem. A local user with network administration privileges could cause a Denial of Service (DoS) by enabling metadata collection on an existing GRE network device through a netlink interface modification request. Because the kernel fails to verify tunnel uniqueness during link modifications, this operation can overwrite shared metadata lookup entries, breaking packet reception for other active tunnel devices in the same network namespace when either device is removed.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Fix deferred kernel Red Hat Enterprise Linux 7 Fix deferred kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred 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 Fix deferred 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-2026-98569 https://nvd.nist.gov/vuln/detail/CVE-2026-98569 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98569.mbox