wifi: mt76: mt7603: initialize global station WCID

Overview

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

wifi: mt76: mt7603: initialize global station WCID

mt7603 uses a driver-private global station WCID for frames that have neither a station nor a vif, including frames injected through a monitor interface. Unlike the core global WCID initialized by mt76_register_device(), this WCID is published without ever being passed to mt76_wcid_init().

Since commit 0335c034e726 ("wifi: mt76: fix race condition related to checking tx queue fill status"), mt76_tx() queues every such frame on the WCID's tx_pending or tx_offchannel queue and links its tx_list. The first injected frame therefore reaches __skb_queue_tail() with an uninitialized sk_buff_head and dereferences a NULL prev pointer.

Initialize the WCID before publishing it.

The fix was tested on an MT7603 PCIe device. Three wildcard probe requests were injected through a monitor interface. The hardware queue head and tail advanced from 0 to 3 and a second radio captured the third request over the air. No oops or reset occurred. After restoring AP mode, a 150 MB transfer also completed without a reset.

Affected

• Linux >= d2defcddfe90b3be0cfccc2482495ab1fb759586 < 99b8bd6323e6fc69615af828522878b7acb77bff
• Linux >= 0335c034e7265d36d956e806f33202c94a8a9860 < e454ec553996f21085657c96c8a605e2d89a81a6
• Linux >= 0335c034e7265d36d956e806f33202c94a8a9860 < dd117d17e8aa2e89f857fb708e5b770709fb81cb
• Linux >= 0335c034e7265d36d956e806f33202c94a8a9860 < 19d6fa087dcf242223645828b8282d4040bad168
• Linux >= 0335c034e7265d36d956e806f33202c94a8a9860 < 456de496b53ae73e6e3020fec815dbdc88aa7c07
• Linux >= 6.6.48 < 6.6.160
• Linux 6.7

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.