lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <xqxkwf6se64yppiwqe5nwkc5tpumxb4rw3bb4g7q346u7zj2da@omdcvtnljntm>
Date: Tue, 14 Oct 2025 17:34:05 +0800
From: "Chia-Lin Kao (AceLan)" <acelan.kao@...onical.com>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>, Andrei Kuchynski <akuchynski@...omium.org>, 
	Ɓukasz Bartosik <ukaszb@...omium.org>, Venkat Jayaraman <venkat.jayaraman@...el.com>, 
	linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] usb: typec: ucsi: Fix workqueue destruction race during
 connector cleanup

On Mon, Oct 13, 2025 at 04:00:17PM +0300, Heikki Krogerus wrote:
> On Sun, Oct 12, 2025 at 10:00:03PM +0800, Chia-Lin Kao (AceLan) wrote:
> > On Thu, Oct 09, 2025 at 05:08:53PM +0300, Heikki Krogerus wrote:
> > > On Thu, Oct 09, 2025 at 09:58:22AM +0800, Chia-Lin Kao (AceLan) wrote:
> > > > On Wed, Oct 08, 2025 at 01:34:35PM +0300, Heikki Krogerus wrote:
> > > > > On Thu, Oct 02, 2025 at 09:30:26AM +0800, Chia-Lin Kao (AceLan) wrote:
> > > > > > During UCSI initialization and operation, there is a race condition where
> > > > > > delayed work items can be scheduled but attempt to queue work after the
> > > > > > workqueue has been destroyed. This occurs in multiple code paths.
> > > > > > 
> > > > > > The race occurs when:
> > > > > > 1. ucsi_partner_task() or ucsi_poll_worker() schedule delayed work
> > > > > > 2. Connector cleanup paths call destroy_workqueue()
> > > > > > 3. Previously scheduled delayed work timers fire after destruction
> > > > > > 4. This triggers warnings and crashes in __queue_work()
> > > > > 
> > > > > What warnings?
> > > > Here is what I got.
> > > > 
> > > > Sep 24 13:24:22 ubuntu kernel: sysfs: cannot create duplicate filename '/devices/platform/USBC000:00/typec/port0/port0.0/partner'
> > > > Sep 24 13:24:22 ubuntu kernel: CPU: 1 UID: 0 PID: 132 Comm: kworker/u64:1 Tainted: G           O       6.14.0-1012-oem #12-Ubuntu
> > > > Sep 24 13:24:22 ubuntu kernel: Tainted: [O]=OOT_MODULE
> > > > Sep 24 13:24:22 ubuntu kernel: Hardware name: Dell Inc. Dell /, BIOS XXXX XX/XX/2025
> > > > Sep 24 13:24:22 ubuntu kernel: Workqueue: USBC000:00-con1 ucsi_poll_worker [typec_ucsi]
> > > > Sep 24 13:24:22 ubuntu kernel: Call Trace:
> > > > Sep 24 13:24:22 ubuntu kernel:  <TASK>
> > > > Sep 24 13:24:22 ubuntu kernel:  dump_stack_lvl+0x76/0xa0
> > > > Sep 24 13:24:22 ubuntu kernel:  dump_stack+0x10/0x20
> > > > Sep 24 13:24:22 ubuntu kernel:  sysfs_warn_dup+0x8a/0xb0
> > > > Sep 24 13:24:22 ubuntu kernel:  sysfs_do_create_link_sd+0xf1/0x100
> > > > Sep 24 13:24:22 ubuntu kernel:  sysfs_create_link+0x21/0x50
> > > > Sep 24 13:24:22 ubuntu kernel:  typec_probe+0x7e/0x100 [typec]
> > > > Sep 24 13:24:22 ubuntu kernel:  ? driver_sysfs_add+0x66/0xd0
> > > > Sep 24 13:24:22 ubuntu kernel:  really_probe+0xee/0x3c0
> > > > Sep 24 13:24:22 ubuntu kernel:  __driver_probe_device+0x8c/0x180
> > > > Sep 24 13:24:22 ubuntu kernel:  driver_probe_device+0x24/0xd0
> > > > Sep 24 13:24:22 ubuntu kernel:  __device_attach_driver+0xcd/0x170
> > > > Sep 24 13:24:22 ubuntu kernel:  ? _pfx__device_attach_driver+0x10/0x10
> > > > Sep 24 13:24:22 ubuntu kernel:  bus_for_each_drv+0x94/0xf0
> > > > Sep 24 13:24:22 ubuntu kernel:  __device_attach+0xb6/0x1d0
> > > > Sep 24 13:24:22 ubuntu kernel:  device_initial_probe+0x13/0x20
> > > > Sep 24 13:24:22 ubuntu kernel:  bus_probe_device+0x9f/0xb0
> > > > Sep 24 13:24:22 ubuntu kernel:  device_add+0x513/0x710
> > > > Sep 24 13:24:22 ubuntu kernel:  device_register+0x1a/0x30
> > > > Sep 24 13:24:22 ubuntu kernel:  typec_register_altmode+0x253/0x3a0 [typec]
> > > > Sep 24 13:24:22 ubuntu kernel:  typec_partner_register_altmode+0xe/0x20 [typec]
> > > > Sep 24 13:24:22 ubuntu kernel:  ucsi_register_altmode.constprop.0+0x30e/0x390 [typec_ucsi]
> > > > Sep 24 13:24:22 ubuntu kernel:  ucsi_register_altmodes+0x162/0x250 [typec_ucsi]
> > > > Sep 24 13:24:22 ubuntu kernel:  ucsi_check_altmodes+0x19/0xb0 [typec_ucsi]
> > > > Sep 24 13:24:22 ubuntu kernel:  ucsi_poll_worker+0x3d/0xf0 [typec_ucsi]
> > > > Sep 24 13:24:22 ubuntu kernel:  process_one_work+0x178/0x3d0
> > > > Sep 24 13:24:22 ubuntu kernel:  worker_thread+0x2de/0x410
> > > > Sep 24 13:24:22 ubuntu kernel:  ? __pfx_worker_thread+0x10/0x10
> > > > Sep 24 13:24:22 ubuntu kernel:  kthread+0xfb/0x230
> > > > Sep 24 13:24:22 ubuntu kernel:  ? __pfx_kthread+0x10/0x10
> > > > Sep 24 13:24:22 ubuntu kernel:  ret_from_fork+0x44/0x70
> > > > Sep 24 13:24:22 ubuntu kernel:  ? __pfx_kthread+0x10/0x10
> > > > Sep 24 13:24:22 ubuntu kernel:  ret_from_fork_asm+0x1a/0x30
> > > > Sep 24 13:24:22 ubuntu kernel:  </TASK>
> > > > Sep 24 13:24:22 ubuntu kernel: typec-thunderbolt port0-partner.1: failed to create symlinks
> > > > Sep 24 13:24:22 ubuntu kernel: typec-thunderbolt port0-partner.1: probe with driver typec-thunderbolt failed with error -17
> > > 
> > > That does not look like anything you described in the commit message?
> > > 
> > > You have there an attempt to register the same alternate mode twice,
> > > but the workqueue seems to be very much alive when that happens.
> > > 
> > > Based on the above this looks like either a race where the driver
> > > really ends up registering the alternate modes multiple times or, and
> > > more likely, the firmware is reporting the same alternate mode
> > > multiple times.
> > > 
> > > Or am I missing something?
> > Here is another one. It's not immediately obvious how this one relates to typec_ucsi.
> > 
> > [  170.605181] ucsi_acpi USBC000:00: con2: failed to register alt modes
> > [  181.868900] ------------[ cut here ]------------
> > [  181.868905] workqueue: cannot queue ucsi_poll_worker [typec_ucsi] on wq USBC000:00-con1
> > [  181.868918] WARNING: CPU: 1 PID: 0 at kernel/workqueue.c:2255 __queue_work+0x420/0x5a0
> > ...
> > [  181.869062] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.17.0-rc7+ #1 PREEMPT(voluntary)
> > [  181.869065] Hardware name: Dell Inc. , BIOS xx.xx.xx xx/xx/2025
> > [  181.869067] RIP: 0010:__queue_work+0x420/0x5a0
> > [  181.869070] Code: 00 00 41 83 e4 01 0f 85 57 fd ff ff 49 8b 77 18 48 8d 93 c0 00 00 00 48 c7 c7 00 8c bc 92 c6 05 27 47 68 02 01 e8 50 24 fd f
> > f <0f> 0b e9 32 fd ff ff 0f 0b e9 1d fd ff ff 0f 0b e9 0f fd ff ff 0f
> > [  181.869072] RSP: 0018:ffffd53c000acdf8 EFLAGS: 00010046
> > [  181.869075] RAX: 0000000000000000 RBX: ffff8ecd0727f200 RCX: 0000000000000000
> > [  181.869076] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> > [  181.869077] RBP: ffffd53c000ace38 R08: 0000000000000000 R09: 0000000000000000
> > [  181.869078] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> > [  181.869079] R13: ffffffff913995e0 R14: ffff8ecc824387a0 R15: ffff8ecc82438780
> > [  181.869081] FS:  0000000000000000(0000) GS:ffff8eec0b92f000(0000) knlGS:0000000000000000
> > [  181.869083] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [  181.869084] CR2: 000005593e67a008 CR3: 0000001f41840002 CR4: 0000000000f72ef0
> > [  181.869086] PKRU: 55555554
> > [  181.869087] Call Trace:
> > [  181.869089]  <IRQ>
> > [  181.869093]  ? sched_clock+0x10/0x30
> > [  181.869098]  ? __pfx_delayed_work_timer_fn+0x10/0x10
> > [  181.869100]  delayed_work_timer_fn+0x19/0x30
> > [  181.869102]  call_timer_fn+0x2c/0x150
> > [  181.869106]  ? __pfx_delayed_work_timer_fn+0x10/0x10
> > [  181.869108]  __run_timers+0x1c6/0x2d0
> > [  181.869111]  run_timer_softirq+0x8a/0x100
> > [  181.869114]  handle_softirqs+0xe4/0x340
> > [  181.869118]  __irq_exit_rcu+0x10e/0x130
> > [  181.869121]  irq_exit_rcu+0xe/0x20
> > [  181.869124]  sysvec_apic_timer_interrupt+0xa0/0xc0
> > [  181.869130]  </IRQ>
> > [  181.869131]  <TASK>
> > [  181.869132]  asm_sysvec_apic_timer_interrupt+0x1b/0x20                                                                                        [  181.869135] RIP: 0010:cpuidle_enter_state+0xda/0x710
> > [  181.869137] Code: 8f f7 fe e8 78 f0 ff ff 8b 53 04 49 89 c7 0f 1f 44 00 00 31 ff e8 86 bf f5 fe 80 7d d0 00 0f 85 22 02 00 00 fb 0f 1f 44 00 0
> > 0 <45> 85 f6 0f 88 f2 01 00 00 4d 63 ee 49 83 fd 0a 0f 83 d8 04 00 00
> > [  181.869139] RSP: 0018:ffffd53c0022be18 EFLAGS: 00000246
> > [  181.869140] RAX: 0000000000000000 RBX: ffff8eeb9f8bf880 RCX: 0000000000000000
> > [  181.869142] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000
> > [  181.869143] RBP: ffffd53c0022be68 R08: 0000000000000000 R09: 0000000000000000
> > [  181.869144] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff93914780
> > [  181.869145] R13: 0000000000000002 R14: 0000000000000002 R15: 0000002a583b0b41
> > [  181.869148]  ? cpuidle_enter_state+0xca/0x710
> > [  181.869151]  cpuidle_enter+0x2e/0x50
> > [  181.869156]  call_cpuidle+0x22/0x60
> > [  181.869160]  do_idle+0x1dc/0x240
> > [  181.869163]  cpu_startup_entry+0x29/0x30
> > [  181.869164]  start_secondary+0x128/0x160
> > [  181.869167]  common_startup_64+0x13e/0x141
> > [  181.869171]  </TASK>
> > [  181.869172] ---[ end trace 0000000000000000 ]---
> > [  226.924460] workqueue USBC000:00-con1: drain_workqueue() isn't complete after 10 tries
> > [  329.470977] ucsi_acpi USBC000:00: error -ETIMEDOUT: PPM init failed
> 
> Okay, so to me it looks like there are two separate issues here.
Yes, there are 2 issues.
> 
> The first one looks like an EC (or PD controller) firmware related
> issue, where the response to the GET_ALTERNATE_MODES command is
> getting corrupted for some reason, and second is this race that you
> see as a consequence from the first FW related issue.
> 
> So this patch is for the second issue - the race. I'll wait for the v2
> from you guys. But I want to solve both issues.
Here is v2 https://lkml.org/lkml/2025/10/13/312

And I have a patch to fix the second issue, will submit it later.
> 
> thanks,
> 
> -- 
> heikki

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ