CVE-2026-31394
Full vulnerability record from the local CVENow database.
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]
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-04-03 16:16:37.597000
Last modified
2026-11-05 22:18:28.293000
View original CVE JSON
{
"id": "CVE-2026-31394",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-04-03T16:16:37.597",
"lastModified": "2026-11-05T22:18:28.293",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmac80211: fix crash in ieee80211_chan_bw_change for AP_VLAN stations\n\nieee80211_chan_bw_change() iterates all stations and accesses\nlink->reserved.oper via sta->sdata->link[link_id]. 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: corrección 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 través 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[también cambia sta -> sdata en ARRAY_SIZE incluso si no importa]"
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/mac80211/chan.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "b27512368591fc959768df1f7dacf2a96b1bd036",
"lessThan": "65c25b588994dd422fea73fa322de56e1ae4a33b",
"versionType": "git",
"status": "affected"
},
{
"version": "b27512368591fc959768df1f7dacf2a96b1bd036",
"lessThan": "5a86d4e920d9783a198e39cf53f0e410fba5fbd6",
"versionType": "git",
"status": "affected"
},
{
"version": "b27512368591fc959768df1f7dacf2a96b1bd036",
"lessThan": "3c6629e859a2211a1fbb4868f915413f80001ca5",
"versionType": "git",
"status": "affected"
},
{
"version": "b27512368591fc959768df1f7dacf2a96b1bd036",
"lessThan": "672e5229e1ecfc2a3509b53adcb914d8b024a853",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/mac80211/chan.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.11",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.11",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.78",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.20",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.19.10",
"lessThanOrEqual": "6.19.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.0",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-05T21:31:59.618538Z",
"id": "CVE-2026-31394",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.11",
"versionEndExcluding": "6.12.78",
"matchCriteriaId": "77CDBE06-9D74-42B8-997B-232CD9BBDC24"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.13",
"versionEndExcluding": "6.18.20",
"matchCriteriaId": "E5571059-6552-48E7-9BEF-3E358C387171"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "6.19.10",
"matchCriteriaId": "96D34333-38BE-4414-9E79-6EB764329581"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
"matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
"matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
"matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
"matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/3c6629e859a2211a1fbb4868f915413f80001ca5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/5a86d4e920d9783a198e39cf53f0e410fba5fbd6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/65c25b588994dd422fea73fa322de56e1ae4a33b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/672e5229e1ecfc2a3509b53adcb914d8b024a853",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
}
]
}