INFO: task syz.0.16:5157 blocked for more than 143 seconds.
      Not tainted 5.15.185-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16        state:D stack:27272 pid: 5157 ppid:  4902 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8484
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0x15e/0x200 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 __wait_on_buffer fs/buffer.c:122 [inline]
 wait_on_buffer include/linux/buffer_head.h:390 [inline]
 __bread_slow fs/buffer.c:1181 [inline]
 __bread_gfp+0x2c2/0x380 fs/buffer.c:1384
 sb_bread include/linux/buffer_head.h:337 [inline]
 qnx6_check_first_superblock+0xa1/0x320 fs/qnx6/inode.c:265
 qnx6_fill_super+0x341/0x1990 fs/qnx6/inode.c:335
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3010
 do_mount fs/namespace.c:3353 [inline]
 __do_sys_mount fs/namespace.c:3561 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
 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: 0033:0x7ff706d8ed29
RSP: 002b:00007ff706007038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff706f7efa0 RCX: 00007ff706d8ed29
RDX: 0000000020000580 RSI: 0000000020000480 RDI: 0000000020000440
RBP: 00007ff706e0ab08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff706f7efa0 R15: 00007ffc29e0abf8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: 
ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90000cc7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff8880242e5240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480
3 locks held by kworker/0:1/13:
 #0: ffff88802a7d8938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90000d27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffffffff8d22a948 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4116
1 lock held by khungtaskd/27:
 #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
6 locks held by kworker/u4:1/144:
2 locks held by kworker/u4:3/401:
2 locks held by getty/3932:
 #0: ffff88802b6ba098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025d62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:6/4783:
 #0: ffff88802a7d8938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000308fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffffffff8d22a948 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4116
1 lock held by syz.0.16/5157:
 #0: ffff88802a81e0e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.1.17/5173:
 #0: ffff888022e860e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.2.18/5189:
 #0: ffff8880792d20e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.3.19/5211:
 #0: ffff8880228d00e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.4.20/5234:
 #0: ffff88807dd400e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.5.21/5256:
 #0: ffff88802a76e0e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.6.22/5278:
 #0: ffff8880724aa0e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.7.23/5307:
 #0: ffff8880798f00e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.8.24/5330:
 #0: 
ffff88807b2160e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
5 locks held by syz-executor/5332:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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: 4370 Comm: kworker/0:11 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events hci_cmd_timeout
RIP: 0010:delay_tsc+0x57/0xc0 arch/x86/lib/delay.c:79
Code: 90 49 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 53 bf 01 00 00 00 e8 46 52 50 fd 65 8b 05 e7 61 01 7c 85 c0 74 1c f3 90 <bf> 01 00 00 00 e8 9f 50 50 fd e8 ca 6e a0 05 39 c5 75 0e 0f 01 f9
RSP: 0018:ffffc9000316f490 EFLAGS: 00000082
RAX: 0000000080000002 RBX: 0000000000000899 RCX: 0000000000000000
RDX: 000000000000008c RSI: ffffffff8a59a720 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000003
R10: fffff5200062de88 R11: 1ffff9200062de88 R12: 000000000000270e
R13: ffffffff963c8be8 R14: 0000008c59a308ed R15: 000000000000061c
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f10512d9e9c CR3: 000000002a301000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 wait_for_xmitr+0xb9/0x260 drivers/tty/serial/8250/8250_port.c:2077
 serial8250_console_putchar+0x1a/0x50 drivers/tty/serial/8250/8250_port.c:3310
 uart_console_write+0xaa/0x100 drivers/tty/serial/serial_core.c:1981
 serial8250_console_write+0xbb5/0xf80 drivers/tty/serial/8250/8250_port.c:3387
 call_console_drivers kernel/printk/printk.c:-1 [inline]
 console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 bt_err+0x108/0x150 net/bluetooth/lib.c:180
 hci_cmd_timeout+0x10a/0x220 net/bluetooth/hci_core.c:2779
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>