CVE-2026-31394 Details
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]
A NULL pointer dereference vulnerability has been identified in the Linux kernel's mac80211 component, specifically affecting stations on AP_VLAN interfaces, such as 4addr WDS clients. The issue arises in the ieee80211_chan_bw_change() function, which iterates through stations and accesses link data. For AP_VLAN stations, the link data is not properly initialized, leading to a NULL pointer dereference when the function attempts to access channel information during Channel Switch Announcement (CSA) processing. This vulnerability has been addressed by modifying the function to correctly resolve the VLAN station data to its parent AP station data before accessing the link information.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for upgrading can be found in the official Linux kernel documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/3c6629e859a2211a1fbb4868f915413f80001ca5 | kernel.org | Patch |
| https://git.kernel.org/stable/c/5a86d4e920d9783a198e39cf53f0e410fba5fbd6 | kernel.org | Patch |
| https://git.kernel.org/stable/c/65c25b588994dd422fea73fa322de56e1ae4a33b | kernel.org | Patch |
| https://git.kernel.org/stable/c/672e5229e1ecfc2a3509b53adcb914d8b024a853 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-476 | NULL Pointer Dereference | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.11, < 6.12.78 >= 6.13, < 6.18.20 >= 6.19, < 6.19.10 7.0 rc1 7.0 rc2 7.0 rc3 7.0 rc4 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | kernel.org |
| May 20, 2026 | Initial Analysis | [email protected] |
| Apr 3, 2026 | New CVE Received | kernel.org |