INFO: task syz-executor:5787 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D
stack:21704 pid:5787 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
wb_wait_for_completion+0x173/0x2a0 fs/fs-writeback.c:192
sync_inodes_sb+0x1c9/0xa10 fs/fs-writeback.c:2772
sync_filesystem+0x171/0x220 fs/sync.c:64
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259
task_work_run+0x1d4/0x260 kernel/task_work.c:245
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x95a/0x2460 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1e9199acb9
RSP: 002b:00007ffd446a9448 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f1e91a047ae RCX: 00007f1e9199acb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 0000000000000000 R09: 00007f1e91a0471f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd446aa700
R13: 00007f1e91a0471f R14: 000055557459a4e8 R15: 00007ffd446ab7d0
Showing all locks held in the system:
2 locks held by kworker/u4:0/11:
#0: ffff8880186f8538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff8880186f8538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
1 lock held by khungtaskd/29:
#0: ffffffff8d12ffe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d12ffe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d12ffe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/0:2/5097:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc900106ffd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900106ffd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
2 locks held by getty/5530:
#0: ffff888020c800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
7 locks held by kworker/0:3/5758:
#0: ffff888147a54d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888147a54d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc9000452fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000452fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#2: ffff8880253bd190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff8880253bd190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
#3: ffff88805fb00190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff88805fb00190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10b/0x8a0 drivers/usb/core/hub.c:2306
#4: ffff88801bef3160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff88801bef3160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
#4: ffff88801bef3160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb6/0x7a0 drivers/base/dd.c:1292
#5: ffffffff8de792a8 (input_mutex){+.+.}-{3:3}, at: __input_unregister_device+0x2ee/0x5f0 drivers/input/input.c:2293
#6: ffffffff8d1359b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#6: ffffffff8d1359b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by syz-executor/5787:
#0: ffff88805bed40e0 (&type->s_umount_key#82){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88805bed40e0 (&type->s_umount_key#82){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88805bed40e0 (&type->s_umount_key#82){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff88814013e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff88814013e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2770
4 locks held by udevd/8843:
#0: ffff88802b539540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
#1: ffff888023c47888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172
#2: ffff88807df2b7c8 (kn->active#24){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88807df2b7c8 (kn->active#24){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
#3: ffff88805fb00190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline]
#3: ffff88805fb00190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf3d/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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:task_has_idle_policy kernel/sched/sched.h:210 [inline]
RIP: 0010:se_is_idle kernel/sched/fair.c:489 [inline]
RIP: 0010:account_entity_enqueue kernel/sched/fair.c:3654 [inline]
RIP: 0010:enqueue_entity+0x420/0x11c0 kernel/sched/fair.c:5337
Code: 8d 70 18 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 2a 06 00 00 41 ff 06 f6 44 24 08 40 74 51 eb 28 4d 8d b7 8c 03 00 00 <4c> 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 ef 06 00 00 41 83
RSP: 0018:ffffc90000106c50 EFLAGS: 00000046
RAX: 1ffff11004f503e4 RBX: ffff888027a81f20 RCX: dffffc0000000000
RDX: ffff88801be4bcb8 RSI: ffff8880b8f3cb20 RDI: ffff888027a81eb8
RBP: ffff8880b8f3c0d0 R08: 1ffff11004f503eb R09: 1ffffffff1d14be5
R10: dffffc0000000000 R11: fffffbfff1d14be6 R12: dffffc0000000000
R13: 1ffff110171e781a R14: ffff888027a8220c R15: ffff888027a81e80
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c81025c130 CR3: 0000000075a43000 CR4: 00000000003506e0
DR0: 000000009e2a517c DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
enqueue_task_fair+0x18d/0x850 kernel/sched/fair.c:6776
enqueue_task+0x182/0x2b0 kernel/sched/core.c:2102
activate_task kernel/sched/core.c:2132 [inline]
ttwu_do_activate+0x1d6/0x7d0 kernel/sched/core.c:3786
ttwu_queue kernel/sched/core.c:4028 [inline]
try_to_wake_up+0x68a/0x1190 kernel/sched/core.c:4349
autoremove_wake_function+0x17/0x100 kernel/sched/wait.c:424
__wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:107
__wake_up_common_lock kernel/sched/wait.c:138 [inline]
__wake_up+0x125/0x1a0 kernel/sched/wait.c:160
nilfs_segctor_sync+0x1c3/0x460 fs/nilfs2/segment.c:2237
writepage_cb+0x67/0x130 mm/page-writeback.c:2559
write_cache_pages+0x736/0x1240 mm/page-writeback.c:2496
do_writepages+0x443/0x630 mm/page-writeback.c:2580
__writeback_single_inode+0x153/0xec0 fs/fs-writeback.c:1635
writeback_sb_inodes+0x7cd/0xf50 fs/fs-writeback.c:1926
wb_writeback+0x46a/0xbf0 fs/fs-writeback.c:2105
wb_do_writeback fs/fs-writeback.c:2252 [inline]
wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
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