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]

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Fri, 03 Apr 2026 16:30:00 +0000

Type Values Removed Values Added
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]
Title mac80211: fix crash in ieee80211_chan_bw_change for AP_VLAN stations
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-04-03T15:15:58.806Z

Reserved: 2026-03-09T15:48:24.085Z

Link: CVE-2026-31394

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-03T16:16:37.597

Modified: 2026-04-03T16:16:37.597

Link: CVE-2026-31394

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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