INFO: task syz-executor:4265 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:22240 pid:4265 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
wb_wait_for_completion+0x162/0x280 fs/fs-writeback.c:191
__writeback_inodes_sb_nr+0x1f3/0x240 fs/fs-writeback.c:2654
sync_filesystem+0x9f/0x220 fs/sync.c:54
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182
task_work_run+0x1ca/0x250 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd88d1901f7
RSP: 002b:00007ffe84b888f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd88d211d7d RCX: 00007fd88d1901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe84b889b0
RBP: 00007ffe84b889b0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe84b89a40
R13: 00007fd88d211d7d R14: 00000000000366e1 R15: 00007ffe84b89a80
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
3 locks held by kworker/0:1/14:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90000137d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#2: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
1 lock held by khungtaskd/28:
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4030:
#0: ffff88814d3ab098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4265:
#0: ffff88807db180e0 (&type->s_umount_key#32){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
2 locks held by syz-executor/4278:
#0: ffff88807cb950b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
#0: ffff88807cb950b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705
#1: ffff88807cb94078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5219
2 locks held by kworker/0:5/4326:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900044b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
3 locks held by kworker/u4:7/4362:
3 locks held by kworker/u4:17/5043:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc9001c26fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd35750 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
1 lock held by syz-executor/6330:
#0: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8cb308b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
1 lock held by syz.2.873/7387:
#0: ffff88807db180e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
3 locks held by syz-executor/7583:
#0: ffff8880577bd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
#0: ffff8880577bd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705
#1: ffff8880577bc078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5219
#2: ffffffff8dea0008 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline]
#2: ffffffff8dea0008 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504
1 lock held by syz.3.942/7622:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7623 Comm: syz.1.941 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:unwind_next_frame+0x2dd/0x20b0 arch/x86/kernel/unwind_orc.c:449
Code: 8e 49 81 fc 8c 5b 2b 8e 0f 83 75 13 00 00 48 c7 c0 8c 5b 2b 8e 49 29 c7 48 c7 c2 38 3b 99 8e 49 c1 ff 02 4f 8d 24 7f 4d 01 e4 <49> 01 d4 49 bd 00 00 00 00 00 fc ff df 0f 85 ed 00 00 00 e9 c5 00
RSP: 0018:ffffc9000c3c73d0 EFLAGS: 00000216
RAX: ffffffff8e96c040 RBX: ffffc9000c3c74a8 RCX: ffffffff8e96c048
RDX: ffffffff8f3a523a RSI: ffffffff8e96c038 RDI: ffffffff8138651f
RBP: ffffffff8a4000cb R08: 0000000000000004 R09: 000000000000000e
R10: fffff52001878ea1 R11: 1ffff92001878e9f R12: 0000000000000012
R13: ffffffff8e96c048 R14: ffffffff8e96c044 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c334aea CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1459 [inline]
free_pcp_prepare mm/page_alloc.c:1509 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479
__vunmap+0x856/0xa00 mm/vmalloc.c:2726
kcov_put kernel/kcov.c:437 [inline]
kcov_close+0x27/0x50 kernel/kcov.c:533
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1ca/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x93e/0x2400 kernel/exit.c:880
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f81a558eec9
Code: Unable to access opcode bytes at 0x7f81a558ee9f.
RSP: 002b:00007f81a63e3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: 0000000000000005 RBX: 00007f81a57e5fa0 RCX: 00007f81a558eec9
RDX: 0000000000000018 RSI: 0000200000000000 RDI: 0000000000000011
RBP: 00007f81a5611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f81a57e6038 R14: 00007f81a57e5fa0 R15: 00007fff03d63878