INFO: task syz.4.127:6320 blocked for more than 143 seconds.
      Not tainted 6.6.102-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.127       state:D stack:25640 pid:6320  ppid:5958   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 sync_bdevs+0x1af/0x330 block/bdev.c:1059
 ksys_sync+0xba/0x150 fs/sync.c:105
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb3efd8ebe9
RSP: 002b:00007fb3f0ca5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fb3effb5fa0 RCX: 00007fb3efd8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb3effb5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb3effb6038 R14: 00007fb3effb5fa0 R15: 00007ffc614eedc8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u4:1/12:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/0:2/1189:
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000487fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000487fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by dhcpcd/5455:
 #0: ffff8880b8f3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
2 locks held by getty/5552:
 #0: ffff88802dd510a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
6 locks held by kworker/1:3/5780:
 #0: ffff888018e99938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888018e99938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000445fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000445fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff888142b6e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #2: ffff888142b6e190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
 #3: ffff8880252db190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #3: ffff8880252db190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
 #4: ffff8880317f5160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #4: ffff8880317f5160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
 #5: ffffffff8cbda410 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:215
1 lock held by udevd/5801:
 #0: ffff888021c464c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
3 locks held by kworker/0:4/5863:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
 #2: ffffffff8cd2fca0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #2: ffffffff8cd2fca0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:878 [inline]
 #2: ffffffff8cd2fca0 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid include/linux/mmzone.h:2011 [inline]
 #2: ffffffff8cd2fca0 (rcu_read_lock_sched){....}-{1:2}, at: __virt_addr_valid+0x18c/0x540 arch/x86/mm/physaddr.c:65
1 lock held by syz.4.127/6320:
 #0: ffff888021c464c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
4 locks held by udevd/6952:
 #0: ffff888065cc28b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
 #1: ffff88801e729888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x55/0x3b0 fs/kernfs/file.c:154
 #2: ffff888076f413e8 (kn->active#25){.+.+}-{0:0}, at: kernfs_seq_start+0x75/0x3b0 fs/kernfs/file.c:155
 #3: ffff8880252db190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:997 [inline]
 #3: ffff8880252db190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by dhcpcd-run-hook/9446:

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5778 Comm: syz-executor Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:set_next_entity+0x1/0x490 kernel/sched/fair.c:5427
Code: 44 89 e1 80 e1 07 80 c1 03 38 c1 7c 08 4c 89 e7 e8 d4 d6 7d 00 41 83 3c 24 00 0f 85 4b fe ff ff e9 24 ff ff ff 0f 1f 40 00 55 <41> 57 41 56 41 55 41 54 53 50 48 89 f3 49 89 fe 48 bd 00 00 00 00
RSP: 0018:ffffc9000448f9b0 EFLAGS: 00000046
RAX: 1ffff110171c78ac RBX: ffff88807dfb5b18 RCX: ffff88807dfb5a01
RDX: ffffc9000448fb90 RSI: ffff88807dfb5a80 RDI: ffff8880b8e3c500
RBP: ffff88807dfb5a80 R08: ffffffff8e4a882f R09: 1ffffffff1c95105
R10: dffffc0000000000 R11: fffffbfff1c95106 R12: ffff8880b8e3c500
R13: ffff88802cd9db18 R14: dffffc0000000000 R15: ffff88802cd9da80
FS:  000055555b6fe500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3647781000 CR3: 0000000026e07000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 pick_next_task_fair+0x43e/0xbd0 kernel/sched/fair.c:8495
 __pick_next_task kernel/sched/core.c:6005 [inline]
 pick_next_task kernel/sched/core.c:6080 [inline]
 __schedule+0x69b/0x44d0 kernel/sched/core.c:6661
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 do_nanosleep+0x1ad/0x5f0 kernel/time/hrtimer.c:2114
 hrtimer_nanosleep+0x15f/0x350 kernel/time/hrtimer.c:2162
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1397 [inline]
 __se_sys_clock_nanosleep+0x2ea/0x370 kernel/time/posix-timers.c:1374
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f11ba5c1463
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d fe 70 1c 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffe94b09db8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f11ba5c1463
RDX: 00007ffe94b09dd0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 000000000000010b R09: 0000000000745d1e
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe94b0a220
R13: 0000000000000004 R14: 00007ffe94b09e0c R15: 00007ffe94b09ea0
 </TASK>