CVE-2026-90357

Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source

AV:AAttack vector, adjacent network

WLAN_S1G_TWT_SETUP action frames carry the TWT element into ieee80211_rx_h_action → ieee80211_process_rx_twt_action → ieee80211_s1g_rx_twt_setup → drv_add_twt_setup → mt7915_mac_add_twt_setup; the triggering bytes arrive over 802.11 radio on the AP’s LAN segment, so the vector is Adjacent.

AC:LAttack complexity, low

After mt7915_mcu_twt_agrt_update(..., MCU_TWT_AGRT_ADD) fails, a second TWT setup from the same STA does memset/INIT_LIST_HEAD on the still-linked msta->twt.flow[] slot because flowid_mask was never set. The attacker induces that ADD failure (MCU timeout or mt76_dma_tx_queue_skb_raw queue-full) with their own traffic, then retries or deauths; not a victim-only race.

PR:NPrivileges required, none

ieee80211_process_rx_twt_action only requires rx->sta on an AP with twt_responder; WLAN_CATEGORY_S1G TWT frames are not robust management frames, so MFP does not gate them. No Linux account or capability is needed: associating as a client to an open or guest mt7915 AP is enough to send the TWT setup.

UI:NUser interaction, none

The attacker sends the TWT Setup action frame and the follow-up retry or deauth; ieee80211_iface_work → ieee80211_s1g_rx_twt_action runs with no local user step. An already-running AP with twt_responder is standing configuration, not victim interaction during the attack.

S:UScope, unchanged

mt7915_mac_add_twt_setup corrupts the host kernel’s dev->twt_list and the mt7915_twt_flow embedded in sta->drv_priv; impact stays inside that kernel security authority and does not cross a VM, IOMMU, or guest-to-host boundary.

C:HConfidentiality impact, high

On DISASSOC, mt7915_mac_twt_teardown_flow returns immediately when flowid_mask is unset, then sta_info_free kfree’s the sta while the node remains on twt_list. A later mt7915_mac_twt_sched_list_add walk reads the freed mt7915_twt_flow, a use-after-free of attacker-reallocatable sta slab.

I:HIntegrity impact, high

The retry path memset/INIT_LIST_HEAD of a still-linked flow, and list_add in mt7915_mac_twt_sched_list_add, write next/prev through corrupted or freed list nodes, yielding a kernel write primitive from list corruption and the DISASSOC use-after-free.

A:HAvailability impact, high

mt7915_mac_twt_sched_list_add walking the corrupted or dangling twt_list oopses on a freed mt7915_twt_flow or spins forever on a self-linked node after INIT_LIST_HEAD, hanging or panicking the AP kernel.