INFO: task udevd:11693 blocked in I/O wait for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:24944 pid:11693 tgid:11693 ppid:4976   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d4/0x5630 kernel/sched/core.c:7239
 __schedule_loop kernel/sched/core.c:7316 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7331
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8159
 folio_wait_bit_common+0x836/0xbc0 mm/filemap.c:1329
 folio_put_wait_locked mm/filemap.c:1498 [inline]
 do_read_cache_folio+0x1ac/0x590 mm/filemap.c:4128
 read_mapping_folio include/linux/pagemap.h:1015 [inline]
 read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
 adfspart_check_POWERTEC+0x9a/0x7a0 block/partitions/acorn.c:451
 check_partition block/partitions/core.c:143 [inline]
 blk_add_partitions block/partitions/core.c:591 [inline]
 bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695
 blkdev_get_whole+0x372/0x510 block/bdev.c:794
 bdev_open+0x324/0xd70 block/bdev.c:1003
 blkdev_open+0x461/0x600 block/fops.c:674
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c44aa7407
RSP: 002b:00007ffe5559d6c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3c45219880 RCX: 00007f3c44aa7407
RDX: 00000000000a0800 RSI: 000055fb4a7cb840 RDI: ffffffffffffff9c
RBP: 000055fb4a7bf910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055fb4a7dc980
R13: 000055fb4a7cd190 R14: 0000000000000000 R15: 000055fb4a7dc980
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/30: 1, last CPU#1:
 #0: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6793
locks held by getty/5367: 2, on CPU#1:
 #0: ffff8880365cb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/11693: 1, on CPU#0:
 #0: ffff888027832350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:991
locks held by kworker/u8:15/12590: 3, on CPU#0:
 #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
 #1: ffffc9001bbbfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc9001bbbfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
 #2: ffffffff90036380 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
locks held by syz-executor/16388: 1, last CPU#1:
 #0: ffffffff9a9807e8 (&obj_hash[i].lock){-.-.}-{2:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff9a9807e8 (&obj_hash[i].lock){-.-.}-{2:2}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff9a9807e8 (&obj_hash[i].lock){-.-.}-{2:2}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
 #0: ffffffff9a9807e8 (&obj_hash[i].lock){-.-.}-{2:2}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz-executor/16398: 1, on CPU#1:
 #0: ffffffff90036380 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
 #0: ffffffff90036380 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3587
locks held by syz-executor/18182: 3, on CPU#0:
 #0: ffff88807b374ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline]
 #0: ffff88807b374ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2681
 #1: ffff88807b3740b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x61f/0x10a0 net/bluetooth/hci_sync.c:5575
 #2: ffffffff8eb604e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8eb604e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
locks held by syz-executor/19809: 5, on CPU#1:
 #0: ffff88806954cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline]
 #0: ffff88806954cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2681
 #1: ffff88806954c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x61f/0x10a0 net/bluetooth/hci_sync.c:5575
 #2: ffffffff901bed80 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2178 [inline]
 #2: ffffffff901bed80 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0x99/0x260 net/bluetooth/hci_conn.c:2745
 #3: ffff88804f0302f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x9f/0x550 net/bluetooth/l2cap_core.c:1809
 #4: ffffffff8eb604e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #4: ffffffff8eb604e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
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: 18182 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__bfs kernel/locking/lockdep.c:1769 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1876 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2812 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3185 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3300 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3924 [inline]
RIP: 0010:__lock_acquire+0x17a5/0x2cf0 kernel/locking/lockdep.c:5253
Code: 00 00 0f 83 84 01 00 00 4e 8b 3c e5 e0 e9 75 96 ff c0 25 ff 0f 00 00 89 05 a8 af d3 14 4d 85 ff 0f 84 ac 01 00 00 49 8b 47 10 <48> 85 c0 0f 84 38 0d 00 00 8b 0d 94 af d3 14 39 48 5c 0f 84 6a ff
RSP: 0018:ffffc9000473f1e0 EFLAGS: 00000082
RAX: ffffffff941a82f8 RBX: 00000000000003dd RCX: ffffffff97070ba8
RDX: ffffffff96fa1298 RSI: ffff8880316e6a08 RDI: 00000000000003dd
RBP: e8b8e337b9024b3f R08: ffffc9000473f1a8 R09: 0000000000000020
R10: 0000000000000000 R11: ffffffff81a30d70 R12: 00000000000000f0
R13: ffff8880316e6a08 R14: ffff8880316e5dc0 R15: ffffffff97070ba8
FS:  0000000000000000(0000) GS:ffff888125024000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055824f249d51 CR3: 000000007f278000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73
 ktime_get+0x45/0x220 kernel/time/timekeeping.c:1002
 clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363
 hrtimer_rearm kernel/time/hrtimer.c:2169 [inline]
 __hrtimer_rearm_deferred+0x36c/0x4b0 kernel/time/hrtimer.c:2189
 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:58 [inline]
 hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:67 [inline]
 irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
 irqentry_exit+0x8d3/0x910 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:finish_task_switch+0x413/0xc60 kernel/sched/core.c:5361
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 97 a5 45 0a e8 92 c9 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 08 17 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc9000473f620 EFLAGS: 00000202
RAX: 000000000008a857 RBX: ffff8880b873c2a0 RCX: 8000000000000001
RDX: 0000000000000006 RSI: ffffffff8e257cad RDI: ffffffff8c4cd780
RBP: ffffc9000473f670 R08: ffffffff90589237 R09: 1ffffffff20b1246
R10: dffffc0000000000 R11: fffffbfff20b1247 R12: ffff8880316e5dc0
R13: ffff8880b873c268 R14: dffffc0000000000 R15: 1ffff110170e7854
 context_switch kernel/sched/core.c:5513 [inline]
 __schedule+0x17dc/0x5630 kernel/sched/core.c:7239
 __schedule_loop kernel/sched/core.c:7316 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7331
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7388
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2178 [inline]
 hci_conn_hash_flush+0x99/0x260 net/bluetooth/hci_conn.c:2745
 hci_dev_close_sync+0x7fc/0x10a0 net/bluetooth/hci_sync.c:5587
 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline]
 hci_unregister_dev+0x232/0x5b0 net/bluetooth/hci_core.c:2681
 vhci_release+0x16d/0x1c0 drivers/bluetooth/hci_vhci.c:700
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1009
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
 __do_sys_exit_group kernel/exit.c:1163 [inline]
 __se_sys_exit_group kernel/exit.c:1161 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161
 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e1a79e0d9
Code: Unable to access opcode bytes at 0x7f0e1a79e0af.
RSP: 002b:00007fff7cc266b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f0e1a835f6c RCX: 00007f0e1a79e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f0e1a835f7e R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00000000000927c0 R14: 00000000000b740f R15: 00007fff7cc26860
 </TASK>