# CVE-2025-21958: linux: In the Linux kernel, the following vulnerability has been resolved:  Revert "openvswitch: switch to per-action label...

CVE-2025-21958 is fixed in 36 products on 1 platform, first by DEBIAN-CVE-2025-21958, released April 1, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-21958
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 1, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  Revert "openvswitch: switch to per-action label counting in conntrack"  Currently, ovs_ct_set_labels() is only called for confirmed conntrack entries (ct) within ovs_ct_commit(). However, if the conntrack entry does not have the labels_ext extension, attempting to allocate it in ovs_ct_get_conn_labels() for a confirmed entry triggers a warning in nf_ct_ext_add():    WARN_ON(nf_ct_is_confirmed(ct));  This happens when the conntrack entry is created externally before OVS increments net->ct.labels_used. The issue has become more likely since commit fcb1aa5163b1 ("openvswitch: switch to per-action label counting in conntrack"), which changed to use per-action label counting and increment net->ct.labels_used when a flow with ct action is added.  Since there’s no straightforward way to fully resolve this issue at the moment, this reverts the commit to avoid breaking existing use cases.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-101.33.4.3.el9uek | [ELSA-2025-20480](https://patchblox.com/security/data/fix/linux/elsa-2025-20480.md) | Jul 17, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.20-1 | [DEBIAN-CVE-2025-21958](https://patchblox.com/security/data/fix/linux/debian-cve-2025-21958.md) | Apr 1, 2025 |
| Linux | linux Debian 14 | 6.12.20-1 | [DEBIAN-CVE-2025-21958](https://patchblox.com/security/data/fix/linux/debian-cve-2025-21958.md) | Apr 1, 2025 |

---

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