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]

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

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

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:7.0:rc1::::::
	cpe:2.3:o:linux:linux_kernel:7.0:rc2::::::
	cpe:2.3:o:linux:linux_kernel:7.0:rc3::::::
	cpe:2.3:o:linux:linux_kernel:7.0:rc4::::::

History

No history.

Information

Published : 2026-04-03 16:16

Updated : 2026-07-24 22:10

NVD link : CVE-2026-31394

Mitre link : CVE-2026-31394

CVE.ORG link : CVE-2026-31394

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-476

NULL Pointer Dereference

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For stations on\nAP_VLAN interfaces (e.g. 4addr WDS clients), sta->sdata points to\nthe VLAN sdata, whose link never participates in chanctx reservations.\nThis leaves link->reserved.oper zero-initialized with chan == NULL,\ncausing a NULL pointer dereference in __ieee80211_sta_cap_rx_bw()\nwhen accessing chandef->chan->band during CSA.\n\nResolve the VLAN sdata to its parent AP sdata using get_bss_sdata()\nbefore accessing link data.\n\n[also change sta->sdata in ARRAY_SIZE even if it doesn't matter]"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmac80211: correcci\u00f3n de un fallo en ieee80211_chan_bw_change para estaciones AP_VLAN\n\nieee80211_chan_bw_change() itera sobre todas las estaciones y accede a link -> reserved.oper a trav\u00e9s de sta -> sdata -> link[link_id]. Para estaciones en interfaces AP_VLAN (p. ej., clientes WDS de 4 direcciones), sta -> sdata apunta al sdata de la VLAN, cuyo enlace nunca participa en las reservas de chanctx. Esto deja link -> reserved.oper inicializado a cero con chan == NULL, causando una desreferencia de puntero NULL en __ieee80211_sta_cap_rx_bw() al acceder a chandef -> chan -> band durante CSA.\n\nResuelve el sdata de la VLAN a su sdata AP padre usando get_bss_sdata() antes de acceder a los datos del enlace.\n\n[tambi\u00e9n cambia sta -> sdata en ARRAY_SIZE incluso si no importa]"}], "lastModified": "2026-07-24T22:10:00.140", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "77CDBE06-9D74-42B8-997B-232CD9BBDC24", "versionEndExcluding": "6.12.78", "versionStartIncluding": "6.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E5571059-6552-48E7-9BEF-3E358C387171", "versionEndExcluding": "6.18.20", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "96D34333-38BE-4414-9E79-6EB764329581", "versionEndExcluding": "6.19.10", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}