INFO: task syz.9.563:8181 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.563       state:D stack:28312 pid: 8181 ppid:  5615 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
 iterate_supers+0xa4/0x1d0 fs/super.c:716
 ksys_sync+0x9d/0x170 fs/sync.c:102
 __ia32_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd0b876a819
RSP: 002b:00007fd0b69a3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd0b89e4090 RCX: 00007fd0b876a819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd0b89e4090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd0b89e4128 R14: 00007fd0b89e4090 R15: 00007ffdecd3def8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by udevd/3559:
 #0: ffff888020be0518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
 #1: ffff8881473fa468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
2 locks held by getty/3953:
 #0: ffff88814c78c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
3 locks held by kworker/0:3/4186:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90002f3fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/1:6/4227:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000316fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
4 locks held by kworker/u4:9/4391:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000481fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8d430c50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #3: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
6 locks held by kworker/0:17/4626:
 #0: ffff888141dc9138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000321fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff888024adf220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #2: ffff888024adf220 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x55e0 drivers/usb/core/hub.c:5827
 #3: ffff888024b9a5c0 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3168 [inline]
 #3: ffff888024b9a5c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5393 [inline]
 #3: ffff888024b9a5c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 #3: ffff888024b9a5c0 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5799 [inline]
 #3: ffff888024b9a5c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2260/0x55e0 drivers/usb/core/hub.c:5881
 #4: ffff88802476fb68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5394 [inline]
 #4: ffff88802476fb68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 #4: ffff88802476fb68 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5799 [inline]
 #4: ffff88802476fb68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x2299/0x55e0 drivers/usb/core/hub.c:5881
 #5: ffffffff8cd9fcf0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x14f/0x18d0 drivers/usb/core/hub.c:3030
1 lock held by syz.0.350/6538:
 #0: ffff888028c020e0 (&type->s_umount_key#85/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.9.563/8181:
 #0: ffff888028c020e0 (&type->s_umount_key#96){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.4.741/9459:
 #0: ffff888028c020e0 (&type->s_umount_key#96){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.4.741/9468:
 #0: ffff888028c020e0 (&type->s_umount_key#96){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
2 locks held by syz-executor/9910:
 #0: ffff888020bebd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
 #1: ffff888147467468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
1 lock held by syz.8.819/10315:
 #0: ffff888028c020e0 (&type->s_umount_key#96){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.3.839/10353:
 #0: ffff888028c020e0 (&type->s_umount_key#96){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz-executor/10778:
 #0: ffff888020be0518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by syz-executor/10881:
 #0: ffff888020be3d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
 #1: ffff888020de8468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
1 lock held by dhcpcd/11920:
 #0: ffff88809854c410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #0: ffff88809854c410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline]
 #0: ffff88809854c410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9910 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4686 [inline]
RIP: 0010:__lock_acquire+0x59a/0x7d10 kernel/locking/lockdep.c:4962
Code: 6c 24 30 0f 85 d0 63 00 00 83 3d f0 a4 d0 14 00 0f 84 fe 01 00 00 31 db 48 81 c3 b8 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 <84> c0 0f 85 33 62 00 00 44 0f b6 33 48 8b 44 24 58 0f b6 04 10 84
RSP: 0018:ffffc900043872a0 EFLAGS: 00000806
RAX: 0000000000000000 RBX: ffffffff8fb5cff8 RCX: ffffffff815d0a3a
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff901d40c0
RBP: ffffc900043874f0 R08: ffffffff901d40c7 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffff888021696478
R13: ffff888021695940 R14: 0000000000000000 R15: ffff888021696458
FS:  00005555787ee500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555adddbc660 CR3: 000000008d2a1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 __mod_lruvec_page_state+0x98/0x330 mm/memcontrol.c:778
 unaccount_page_cache_page+0x449/0x870 mm/filemap.c:198
 __delete_from_page_cache+0xbe/0x6d0 mm/filemap.c:231
 delete_from_page_cache+0x121/0x190 mm/filemap.c:266
 truncate_inode_page+0x8d/0xb0 mm/truncate.c:219
 shmem_undo_range+0x53c/0x1930 mm/shmem.c:960
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145
 evict+0x4c9/0x8d0 fs/inode.c:647
 __dentry_kill+0x431/0x650 fs/dcache.c:586
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xd8/0x1a0 fs/dcache.c:893
 __fput+0x5ee/0x930 fs/file_table.c:319
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f59d2111a57
Code: a2 c7 05 9c fc 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe5aa0e768 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f59d21a6048 RCX: 00007f59d2111a57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe5aa0e820
RBP: 00007ffe5aa0e820 R08: 00007ffe5aa0f820 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe5aa0f8b0
R13: 00007f59d21a6048 R14: 0000000000061364 R15: 00007ffe5aa0f8f0
 </TASK>