Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-07-25T00:00:00 kernel: wifi: mt76: mt7921/mt7925: fix NULL dereference in CSA beacon 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-476

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921/mt7925: fix NULL dereference in CSA beacon This patch is based on a BUG as reported by Bongani Hlope at https://lore.kernel.org/all/20260502125824.425d7159@bongani-mini.home.org.za/ When a channel-switch announcement (CSA) beacon is received, cfg80211 queues a wiphy work item that eventually calls mt7921_channel_switch_rx_beacon(). If the station disconnects (or the channel context is otherwise torn down) between the time the work is queued and the time it runs, the driver's dev->new_ctx pointer can already have been cleared to NULL. mt7921_channel_switch_rx_beacon() then dereferences new_ctx unconditionally, triggering a NULL pointer dereference at address 0x0: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:mt7921_channel_switch_rx_beacon+0x1f/0x100 [mt7921_common] The same missing guard exists in mt7925_channel_switch_rx_beacon(), which shares the same code pattern introduced by the same commit. Add an early-return NULL check for dev->new_ctx in both mt7921_channel_switch_rx_beacon() and mt7925_channel_switch_rx_beacon(). When new_ctx is NULL there is no pending channel switch to process, so returning immediately is the correct and safe action. Oops-Analysis: http://oops.fenrus.org/reports/lkml/20260502125824.425d7159@bongani-mini.home.org.za/report.html

A flaw was found in the Linux kernel's mt76 Wi-Fi driver, affecting mt7921 and mt7925 chipsets. When a channel-switch announcement (CSA) beacon is received, a timing issue can occur if a station disconnects before a queued work item processes the beacon. This can lead to a NULL pointer dereference in the mt7921_channel_switch_rx_beacon() or mt7925_channel_switch_rx_beacon() functions, causing a system crash. A remote attacker could potentially exploit this vulnerability to trigger a Denial of Service (DoS).

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt Red Hat Hardened Images Not affected erlang27 https://www.cve.org/CVERecord?id=CVE-2026-64325 https://nvd.nist.gov/vuln/detail/CVE-2026-64325 https://lore.kernel.org/linux-cve-announce/2026072512-CVE-2026-64325-7fc9@gregkh/T