INFO: task kworker/1:3:4946 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/1:3     state:D stack:19648 pid:4946  tgid:4946  ppid:2     
task:kworker/1:3     state:D stack:19648 pid:4946  tgid:4946  ppid:2      task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
 __flush_work+0xa63/0xca0 kernel/workqueue.c:4448
 __cancel_work_sync+0xbf/0x110 kernel/workqueue.c:4568
 __mmc_stop_host drivers/mmc/core/core.c:2368 [inline]
 mmc_stop_host+0xd9/0x460 drivers/mmc/core/core.c:2373
 mmc_remove_host+0x15/0x60 drivers/mmc/core/host.c:681
 vub300_disconnect+0x154/0x2f0 drivers/mmc/host/vub300.c:2387
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 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>
INFO: task kworker/1:4:3411 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/1:4     state:D stack:20832 pid:3411  tgid:3411  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_freezable mmc_rescan
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
 mmc_wait_for_req_done+0x37/0x490 drivers/mmc/core/core.c:408
 mmc_wait_for_cmd+0x183/0x2a0 drivers/mmc/core/core.c:645
 mmc_io_rw_direct_host drivers/mmc/core/sdio_ops.c:83 [inline]
 sdio_reset+0xf4/0x3a0 drivers/mmc/core/sdio_ops.c:209
 mmc_rescan_try_freq drivers/mmc/core/core.c:2121 [inline]
 mmc_rescan+0x6eb/0x1040 drivers/mmc/core/core.c:2316
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 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:
locks held by pr/ttyS0/16: 2, last CPU#1:
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
 #1: ffffffff9ad31098 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9ad31098 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by kworker/1:3/4946: 5, on CPU#1:
 #0: ffff88801eeb0540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801eeb0540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801eeb0540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801eeb0540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9001054fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9001054fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9001054fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9001054fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff888029f251d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff888029f251d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
 #3: ffff8880794f61d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #3: ffff8880794f61d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2341
 #4: ffff8880794f11a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff8880794f11a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
 #4: ffff8880794f11a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
locks held by getty/5370: 2, on CPU#1:
 #0: ffff888021b060a0 (&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
locks held by kworker/1:4/3411: 2, on CPU#1:
 #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90004607c40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90004607c40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90004607c40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90004607c40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz-executor/22128: 2, last CPU#1:
 #0: ffff88807b15e460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff888055f2a0b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff888055f2a0b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff888055f2a0b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff888055f2a0b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5092

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0x38b/0x480 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: 16 Comm: pr/ttyS0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:preempt_count_sub+0x0/0x180 kernel/sched/core.c:6016
Code: c1 7c a1 48 c7 c7 84 44 7a 90 e8 1b a7 a2 00 eb 93 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 56 53 48 bb 00 00 00 00 00 fc ff df 65 4c 8b 35
RSP: 0018:ffffc900001578b0 EFLAGS: 00000016
RAX: 0000000066bc184e RBX: 0000000000000899 RCX: 0000000000000001
RDX: 00000000000002e5 RSI: ffffffff8c6d9360 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8be266c0 R12: 1ffffffff35a626d
R13: 00000000ffffffff R14: 000002e566bc0f5c R15: 00000000000008f2
FS:  0000000000000000(0000) GS:ffff888124dda000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3e571aedc0 CR3: 000000007a474000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 delay_tsc+0xa3/0xd0 arch/x86/lib/delay.c:94
 udelay include/asm-generic/delay.h:62 [inline]
 wait_for_lsr+0x147/0x2f0 drivers/tty/serial/8250/8250_port.c:2019
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
 __serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3345
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
 serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
 kthread+0x38b/0x480 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>