CVE-2026-68194

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

wifi: mt76: mt7921: drop TXRX_NOTIFY on non-mmio buses

PKT_TYPE_TXRX_NOTIFY is an mmio-only event, but mt7921_rx_check() and

mt7921_queue_rx_skb() dispatch it to mt7921_mac_tx_free() on every bus.

mt7921_mac_tx_free() cleans the DMA tx queues with

mt76_queue_tx_cleanup(), which calls queue_ops->tx_cleanup(). Only the

mmio queue ops implement that callback; on USB and SDIO it is NULL, so

a TXRX_NOTIFY there calls a NULL pointer in the RX worker:

BUG: kernel NULL pointer dereference, address: 0000000000000000

RIP: 0010:0x0

Call Trace:

mt7921_mac_tx_free+0x64/0x310 [mt7921_common]

mt7921_rx_check+0x5f/0xf0 [mt7921_common]

mt76u_rx_worker+0x1b9/0x620 [mt76_usb]

Drop the event on non-mmio buses via mt76_is_mmio(), as in

commit 5683e1488aa9 ("wifi: mt76: connac: do not check WED status for

non-mmio devices").

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References