# CVE-2026-31394: mac80211: fix crash in ieee80211_chan_bw_change for AP_VLAN stations

CVE-2026-31394 is fixed in 46 products on 1 platform, first by DEBIAN-CVE-2026-31394, released April 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-31394
- Priority: Routine
- CVSS: 5.5 (Moderate)
- EPSS: 0.0012
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 3, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31394

## Description

In the Linux kernel, the following vulnerability has been resolved:  mac80211: fix crash in ieee80211_chan_bw_change for AP_VLAN stations  ieee80211_chan_bw_change() iterates all stations and accesses link->reserved.oper via sta->sdata->link[link_id]. For stations on AP_VLAN interfaces (e.g. 4addr WDS clients), sta->sdata points to the VLAN sdata, whose link never participates in chanctx reservations. This leaves link->reserved.oper zero-initialized with chan == NULL, causing a NULL pointer dereference in __ieee80211_sta_cap_rx_bw() when accessing chandef->chan->band during CSA.  Resolve the VLAN sdata to its parent AP sdata using get_bss_sdata() before accessing link data.  [also change sta->sdata in ARRAY_SIZE even if it doesn't matter]

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.55.1.150700.17.33.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_15 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | kernel-uek ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.85-1 | [DEBIAN-CVE-2026-31394](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31394.md) | Apr 3, 2026 |
| Linux | linux Debian 14 | 6.19.10-1 | [DEBIAN-CVE-2026-31394](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31394.md) | Apr 3, 2026 |

---

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