CVE-2026-80934
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames
mt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames (MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise FW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes the per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the fw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is always zero, so the unmap loop runs zero times and the skb DMA mapping in buf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the generic DMA-ring cleanup skips it as well.
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Each AddBA req therefore leaks one TX DMA mapping, roughly one per (re)association. With WED enabled these mappings are bounced through the WED swiotlb pool, so under continuous client reconnect churn the pool is exhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi MCU and other on-SoC consumers.
Keep the deferred (token release) unmap that the design relies on, and add an mt7996-specific txp unmap that inspects MT_TXD7_MAC_TXD and unmaps buf[1] from the MAC-TXP layout for those frames, delegating to mt76_connac_txp_skb_unmap() otherwise.
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.21%
- Percentil entre todas las CVEs puntuadas: 10
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-80934",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "cb6ebbdffef2a888b95f121637cd1fad473919c6",
"lessThan": "01f2e0da8548f82d704b65b513026cfedc5f8962",
"versionType": "git"
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{
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{
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"versionType": "git"
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{
"status": "affected",
"version": "91a5a48702e948e45df01a4f2fd54a0b0d0d6efb",
"versionType": "git"
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{
"status": "affected",
"version": "6.17.8",
"lessThan": "6.18",
"versionType": "semver"
}
],
"programFiles": [
"drivers/net/wireless/mediatek/mt76/mt7996/mac.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/wireless/mediatek/mt76/mt7996/mac.c"
],
"defaultStatus": "affected"
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]
}
],
"published": "2026-09-11T20:18:57.280",
"references": [
{
"url": "https://git.kernel.org/stable/c/01f2e0da8548f82d704b65b513026cfedc5f8962",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b754d3a6d44c53d9853eba374d8a7ef279a9d00a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/deaa2e3656937fbbe312f0ee2616c756c6e2511f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames\n\nmt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames\n(MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise\nFW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes\nthe per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the\nfw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is\nalways zero, so the unmap loop runs zero times and the skb DMA mapping in\nbuf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the\ngeneric DMA-ring cleanup skips it as well.\n\nEach AddBA req therefore leaks one TX DMA mapping, roughly one per\n(re)association. With WED enabled these mappings are bounced through the\nWED swiotlb pool, so under continuous client reconnect churn the pool is\nexhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi\nMCU and other on-SoC consumers.\n\nKeep the deferred (token release) unmap that the design relies on, and add\nan mt7996-specific txp unmap that inspects MT_TXD7_MAC_TXD and unmaps\nbuf[1] from the MAC-TXP layout for those frames, delegating to\nmt76_connac_txp_skb_unmap() otherwise."
}
],
"lastModified": "2026-09-11T20:18:57.280",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}