CVE-2026-31394

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]

Score

CVSS 3.1 5.5 Medium

Status

Analyzed - 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-04-03

Last modified

2026-05-11

Weaknesses

CWE-476

Affected products

• Linux Kernel (Linux)

References

• https://git.kernel.org/stable/c/3c6629e859a2211a1fbb4868f915413f80001ca5
• https://git.kernel.org/stable/c/5a86d4e920d9783a198e39cf53f0e410fba5fbd6
• https://git.kernel.org/stable/c/65c25b588994dd422fea73fa322de56e1ae4a33b
• https://git.kernel.org/stable/c/672e5229e1ecfc2a3509b53adcb914d8b024a853