INFO: task kworker/0:8:23918 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:8     state:D stack:22760 pid:23918 tgid:23918 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 usb_kill_urb+0x1cf/0x2f0 drivers/usb/core/urb.c:717
 usb_start_wait_urb+0x22a/0x5b0 drivers/usb/core/message.c:74
 usb_internal_control_msg drivers/usb/core/message.c:117 [inline]
 usb_control_msg+0x234/0x3e0 drivers/usb/core/message.c:167
 get_bMaxPacketSize0 drivers/usb/core/hub.c:4851 [inline]
 hub_port_init+0xb0b/0x28c0 drivers/usb/core/hub.c:5047
 hub_port_connect drivers/usb/core/hub.c:5496 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x24e8/0x4d30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5382:
 #0: ffff888035f570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
2 locks held by kworker/0:4/5715:
 #0: ffff88813fe4f140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88813fe4f140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc90004a57c40 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc90004a57c40 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
5 locks held by kworker/0:8/23918:
 #0: ffff888021efa940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff888021efa940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc9000571fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc9000571fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #2: ffff88802b1411d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
 #2: ffff88802b1411d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5899
 #3: ffff88802b175568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 #3: ffff88802b175568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
 #3: ffff88802b175568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #3: ffff88802b175568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #3: ffff88802b175568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5953
 #4: ffff88802b060e60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
 #4: ffff88802b060e60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #4: ffff88802b060e60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #4: ffff88802b060e60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5953
3 locks held by kworker/1:0/28680:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17198 Comm: kworker/u8:6 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: krds_cp_wq#19/0 rds_connect_worker
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x70 kernel/kcov.c:217
Code: 38 9e 79 11 65 8b 15 59 9e 79 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 24 17 00 00 00 74 2c 8b 91 f8 16 00 00 <83> fa 02 75 21 48 8b 91 00 17 00 00 48 8b 32 48 8d 7e 01 8b 89 fc
RSP: 0018:ffffc90003d06e68 EFLAGS: 00000046
RAX: ffffffff8168917d RBX: ffff8880a6e019ae RCX: ffff888089c0be00
RDX: 0000000040000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880a6e00007 R09: 1ffff11014dc0000
R10: dffffc0000000000 R11: ffffed1014dc0001 R12: ffff8880a6e00000
R13: dffffc0000000000 R14: ffff888089c0be00 R15: ffff888089c0be20
FS:  0000000000000000(0000) GS:ffff888125320000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559731632088 CR3: 000000000e746000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000be70000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 _static_cpu_has arch/x86/include/asm/cpufeature.h:101 [inline]
 update_task_stack arch/x86/include/asm/switch_to.h:75 [inline]
 __switch_to+0xc5d/0x1420 arch/x86/kernel/process_64.c:674
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 41 a0 12 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 2b eb 9d 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 10 a1 15 0a cc 48 8d 3d 78 71 94
RSP: 0018:ffffc90003d07200 EFLAGS: 00000286
RAX: 38816f1f65bef300 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000272b758c RSI: ffffffff8e25db1e RDI: ffffffff8c2ab780
RBP: ffffffff8176e21f R08: ffffffff8176e21f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8e959c20 R12: 0000000000000002
R13: ffffffff8e959c20 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:840 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
 unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2705 [inline]
 slab_free mm/slub.c:6405 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6720
 ref_tracker_free+0x518/0x830 lib/ref_tracker.c:339
 __netns_tracker_free include/net/net_namespace.h:384 [inline]
 sk_net_refcnt_upgrade+0x8c/0x130 net/core/sock.c:2399
 rds_tcp_tune+0x44e/0x920 net/rds/tcp.c:529
 rds_tcp_conn_path_connect+0x2fa/0x920 net/rds/tcp_connect.c:137
 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>