CVE-2026-74441: usb: typec: ucsi: Fix race condition and ordering in port unregistration

From: Greg Kroah-Hartman <[email protected]>

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

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

usb: typec: ucsi: Fix race condition and ordering in port unregistration

A synchronization issue exists during port unregistration where pending
partner work items can race against workqueue destruction, leading to
use-after-free conditions:

  cros_ec_ucsi cros_ec_ucsi.3.auto: error -ETIMEDOUT: PPM init failed
  BUG: kernel NULL pointer dereference, address: 0000000000000000
  RIP: 0010:__queue_work+0x83/0x4a0
  Call Trace:
    <IRQ>
    __cfi_delayed_work_timer_fn+0x10/0x10
    run_timer_softirq+0x3b6/0xbd0
    sched_clock_cpu+0xc/0x110
    irq_exit_rcu+0x18d/0x330
    fred_sysvec_apic_timer_interrupt+0x5e/0x80

Fix this by ensuring strict ordering and proper serialization during
teardown:

1. Move ucsi_unregister_partner() to the beginning of the teardown
sequence and protect it under the connector mutex lock.
2. Ensure all pending partner tasks are explicitly flushed and finished
before the workqueue is destroyed.
3. Switch from mod_delayed_work() to a cancel_delayed_work() and
queue_delayed_work() sequence. This guarantees that items currently marked
as pending won't be scheduled an additional time, preventing a double
release of resources which leads to the following crash:

  Oops: general protection fault, probably for non-canonical address
    0xdead000000000122: 0000 [#1] SMP NOPTI
  Workqueue: cros_ec_ucsi.3.auto-con2 ucsi_poll_worker
  RIP: 0010:ucsi_poll_worker+0x65/0x1e0
  Call Trace:
  <TASK>
    process_scheduled_works+0x218/0x6d0
    worker_thread+0x188/0x3f0
    __cfi_worker_thread+0x10/0x10
    kthread+0x226/0x2a0

To ensure these rules are applied identically across both the normal
teardown and the ucsi_init() error paths, consolidate the cleanup logic
into a new helper, ucsi_unregister_port().

The Linux kernel CVE team has assigned CVE-2026-74441 to this issue.


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

	Issue introduced in 5.16 with commit b9aa02ca39a49740926c2c450a1505a4a0f8954a and fixed in 6.6.151 with commit 07f8aaffee705e552c1f723ac8bf7eb137ad59c2
	Issue introduced in 5.16 with commit b9aa02ca39a49740926c2c450a1505a4a0f8954a and fixed in 6.12.103 with commit 11483d80267db97fbe49f2df66385434256cc3b0
	Issue introduced in 5.16 with commit b9aa02ca39a49740926c2c450a1505a4a0f8954a and fixed in 6.18.44 with commit 3f7b3728dd9011c915cbeaea77274ebe8366550d
	Issue introduced in 5.16 with commit b9aa02ca39a49740926c2c450a1505a4a0f8954a and fixed in 7.1.8 with commit bc7a0f721123ea260a42f1ded06dab844ba49434
	Issue introduced in 5.16 with commit b9aa02ca39a49740926c2c450a1505a4a0f8954a and fixed in 7.2-rc5 with commit 7aa7d4bf9d3fa9a6a47b640ad103ab433b7ff261

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-2026-74441
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/usb/typec/ucsi/ucsi.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/07f8aaffee705e552c1f723ac8bf7eb137ad59c2
	https://git.kernel.org/stable/c/11483d80267db97fbe49f2df66385434256cc3b0
	https://git.kernel.org/stable/c/3f7b3728dd9011c915cbeaea77274ebe8366550d
	https://git.kernel.org/stable/c/bc7a0f721123ea260a42f1ded06dab844ba49434
	https://git.kernel.org/stable/c/7aa7d4bf9d3fa9a6a47b640ad103ab433b7ff261