CVE-2026-80938: wifi: mt76: mt7615: avoid waiting for mac work under the mt76 mutex

CVE-2026-80938: wifi: mt76: mt7615: avoid waiting for mac work under the mt76 mutex

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

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

wifi: mt76: mt7615: avoid waiting for mac work under the mt76 mutex

mt7615_suspend() acquired the mt76 mutex and then called
cancel_delayed_work_sync() on mac_work.  mt7615_mac_work() acquires the
same mutex via mt7615_mutex_acquire() at the top of the worker, so if
mac_work is already running and blocked on the mutex, the suspend path
deadlocks waiting for the work it holds the mutex against.

Flush scan_work and mac_work before taking the mutex, matching the
suspend paths in mt7921 and mt7925.  scan_work only takes the mt76
spinlock, but moving it keeps the sequence consistent.  This also keeps
mac_work from running over an already suspended HIF, which the previous
split (async cancel under the lock, sync cancel after release) would
have allowed.

The Linux kernel CVE team has assigned CVE-2026-80938 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.8 with commit c6bf20109a3fae92402cb76ad709ec5256bcd169 and fixed in 6.12.109 with commit 3114d479f2a1d31b2e6214c395794c6e5715e579
	Issue introduced in 5.8 with commit c6bf20109a3fae92402cb76ad709ec5256bcd169 and fixed in 6.18.50 with commit 4506e229b2e468b8c64bcf52c50c41a3bf2e633e
	Issue introduced in 5.8 with commit c6bf20109a3fae92402cb76ad709ec5256bcd169 and fixed in 7.2.4 with commit 44be85af3e1772ffb3332feafedad2a73b22854c
	Issue introduced in 5.8 with commit c6bf20109a3fae92402cb76ad709ec5256bcd169 and fixed in 7.3-rc1 with commit bda8324270b1ac91bfba1df8928e0570e29759e8

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-80938
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/wireless/mediatek/mt76/mt7615/main.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/3114d479f2a1d31b2e6214c395794c6e5715e579
	https://git.kernel.org/stable/c/4506e229b2e468b8c64bcf52c50c41a3bf2e633e
	https://git.kernel.org/stable/c/44be85af3e1772ffb3332feafedad2a73b22854c
	https://git.kernel.org/stable/c/bda8324270b1ac91bfba1df8928e0570e29759e8