INFO: task syz.3.51:6136 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:syz.3.51        state:D stack:25640 pid:6136  tgid:6135  ppid:5606   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 io_schedule+0x80/0xe0 kernel/sched/core.c:8154
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __wait_on_bit_lock+0xe0/0x4a0 kernel/sched/wait_bit.c:93
 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120
 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline]
 __lock_buffer fs/buffer.c:68 [inline]
 lock_buffer include/linux/buffer_head.h:434 [inline]
 __block_write_full_folio+0x55c/0xdd0 fs/buffer.c:1888
 blkdev_writepages+0xef/0x1b0 block/fops.c:485
 do_writepages+0x338/0x560 mm/page-writeback.c:2571
 filemap_writeback mm/filemap.c:387 [inline]
 filemap_fdatawrite_range mm/filemap.c:412 [inline]
 filemap_write_and_wait_range+0x338/0x3f0 mm/filemap.c:684
 hfs_file_fsync+0x116/0x150 fs/hfs/inode.c:697
 generic_write_sync include/linux/fs.h:2661 [inline]
 generic_file_write_iter+0x283/0x330 mm/filemap.c:4505
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61e/0xbb0 fs/read_write.c:687
 ksys_pwrite64 fs/read_write.c:794 [inline]
 __do_sys_pwrite64 fs/read_write.c:802 [inline]
 __se_sys_pwrite64 fs/read_write.c:799 [inline]
 __x64_sys_pwrite64+0x199/0x230 fs/read_write.c:799
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f344f0bce59
RSP: 002b:00007f344d316028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f344f335fa0 RCX: 00007f344f0bce59
RDX: 0000000000000048 RSI: 00002000000001c0 RDI: 0000000000000005
RBP: 00007f344f152e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f344f336038 R14: 00007f344f335fa0 R15: 00007fffc041f968
 </TASK>
INFO: task syz.3.51:6150 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:syz.3.51        state:D stack:24184 pid:6150  tgid:6135  ppid:5606   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 io_schedule+0x80/0xe0 kernel/sched/core.c:8154
 folio_wait_bit_common+0x83c/0xbc0 mm/filemap.c:1323
 folio_lock include/linux/pagemap.h:1157 [inline]
 __find_get_block_slow fs/buffer.c:242 [inline]
 find_get_block_common+0x34f/0xe10 fs/buffer.c:1386
 bdev_getblk+0x58/0x6e0 include/linux/gfp.h:-1
 __bread_gfp+0x89/0x380 fs/buffer.c:1493
 sb_bread include/linux/buffer_head.h:348 [inline]
 hfs_mdb_commit+0xac7/0x1160 fs/hfs/mdb.c:344
 hfs_sync_fs+0x1d/0x30 fs/hfs/super.c:38
 sync_filesystem+0xed/0x250 fs/sync.c:56
 hfs_reconfigure+0x66/0x270 fs/hfs/super.c:122
 reconfigure_super+0x232/0x8f0 fs/super.c:1020
 do_remount fs/namespace.c:3407 [inline]
 path_mount+0xd4b/0x1040 fs/namespace.c:4153
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f344f0be0ca
RSP: 002b:00007f344d2d3e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f344d2d3ee0 RCX: 00007f344f0be0ca
RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000
RBP: 0000200000000f40 R08: 00007f344d2d3ee0 R09: 0000000003b4a468
R10: 0000000003b4a468 R11: 0000000000000246 R12: 0000200000000f00
R13: 00007f344d2d3ea0 R14: 0000000000000000 R15: 0000200000001040
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/11:
6 locks held by kworker/u8:0/12:
7 locks held by kworker/u8:1/14:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:3/55:
6 locks held by kworker/u8:4/67:
5 locks held by kworker/u8:5/90:
7 locks held by kworker/u8:6/256:
5 locks held by kworker/u8:9/1316:
5 locks held by kworker/u8:10/1447:
3 locks held by kworker/u8:11/1512:
 #0: ffff88801dadc138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801dadc138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc90006e17c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc90006e17c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #2: ffff88801b6d40d0 (&type->s_umount_key#43){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:566
5 locks held by kworker/u8:12/3284:
1 lock held by udevd/4964:
2 locks held by getty/5351:
 #0: ffff888031d5e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
7 locks held by syz-executor/5605:
 #0: ffff88802bbb20d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88802bbb20d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88802bbb20d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509
 #1: ffff88805a31b190 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x5f7/0xc60 fs/btrfs/transaction.c:299
 #2: ffff88805a31b1b8 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x5f7/0xc60 fs/btrfs/transaction.c:299
 #3: ffff88805a31b1e0 (btrfs_trans_commit_prep){.+.+}-{0:0}, at: btrfs_commit_transaction+0x182/0x30b0 fs/btrfs/transaction.c:2239
 #4: ffff888033d3ca28 (&head_ref->mutex){+.+.}-{4:4}, at: btrfs_delayed_ref_lock+0x88/0x2b0 fs/btrfs/delayed-ref.c:381
 #5: ffff888030b465c8 (btrfs-extent-00){++++}-{4:4}, at: btrfs_tree_lock_nested+0x45/0x250 fs/btrfs/locking.c:189
 #6: ffff888060b4d940 (&xa->xa_lock#10){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline]
 #6: ffff888060b4d940 (&xa->xa_lock#10){+.+.}-{3:3}, at: __filemap_add_folio+0x97b/0x11d0 mm/filemap.c:875
2 locks held by kworker/1:3/5611:
 #0: ffff88801a043138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801a043138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc90004cdfc40 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc90004cdfc40 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
11 locks held by kworker/1:5/5619:
1 lock held by udevd/5802:
2 locks held by udevd/5805:
2 locks held by syz.3.51/6136:
 #0: ffff888066560500 (sb_writers#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline]
 #0: ffff888066560500 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
 #1: ffff8880628f63f0 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff8880628f63f0 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: hfs_file_fsync+0x9d/0x150 fs/hfs/inode.c:688
1 lock held by syz.3.51/6150:
 #0: ffff8880665600d0 (&type->s_umount_key#60){+.+.}-{4:4}, at: do_remount fs/namespace.c:3404 [inline]
 #0: ffff8880665600d0 (&type->s_umount_key#60){+.+.}-{4:4}, at: path_mount+0xd04/0x1040 fs/namespace.c:4153
5 locks held by syz-executor/6295:
2 locks held by syz.0.283/7740:
 #0: ffff88803d5c0500 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff888060b06240 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff888060b06240 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff888060b06240 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff888060b06240 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4951
2 locks held by udevadm/7776:
 #0: ffffffff8e6fd498 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #0: ffffffff8e6fd498 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #0: ffffffff8e6fd498 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline]
 #0: ffffffff8e6fd498 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_perm+0x251/0x560 security/tomoyo/file.c:826
 #1: ffff88801a016d58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #1: ffff88801a016d58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3772 [inline]
 #1: ffff88801a016d58 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x89/0x5b0 mm/slub.c:7197
1 lock held by udevadm/7779:
2 locks held by syz.1.285/7781:
4 locks held by syz.2.287/7783:
2 locks held by syz-executor/7784:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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+0x388/0x470 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:408
Code: 9a 89 fc 44 89 f9 d3 e5 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 4c fe f2 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000167a70 EFLAGS: 00000202
RAX: 0000000000000072 RBX: 0000000000000072 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000003f8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853b8df0 R12: dffffc0000000000
R13: ffffffff99b7aa20 R14: ffffffff99b7aaa0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888126211000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb926965000 CR3: 000000003c21e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_port_out include/linux/serial_core.h:813 [inline]
 serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3239 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
 serial8250_console_write+0x1201/0x1b40 drivers/tty/serial/8250/8250_port.c:3379
 console_emit_next_record kernel/printk/printk.c:3163 [inline]
 console_flush_one_record+0x642/0xb50 kernel/printk/printk.c:3269
 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
 kthread+0x388/0x470 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>