INFO: task kworker/u10:1:18384 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:1   state:D stack:23544 pid:18384 tgid:18384 ppid:2      task_flags:0x4248160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 io_schedule+0xbf/0x130 kernel/sched/core.c:7871
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x93d/0x1320 fs/jbd2/transaction.c:1092
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:242
 ext4_mb_mark_context+0x175/0xda0 fs/ext4/mballoc.c:4081
 ext4_mb_mark_diskspace_used+0x466/0x8c0 fs/ext4/mballoc.c:4211
 ext4_mb_new_blocks+0xa5b/0x4f70 fs/ext4/mballoc.c:6313
 ext4_ext_map_blocks+0x1cc0/0x5fe0 fs/ext4/extents.c:4383
 ext4_map_create_blocks fs/ext4/inode.c:609 [inline]
 ext4_map_blocks+0x570/0x1400 fs/ext4/inode.c:811
 mpage_map_one_extent fs/ext4/inode.c:2374 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2468 [inline]
 ext4_do_writepages+0x1ffa/0x3cf0 fs/ext4/inode.c:2931
 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3025
 do_writepages+0x277/0x600 mm/page-writeback.c:2604
 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1719
 writeback_sb_inodes+0x60d/0xfa0 fs/fs-writeback.c:2015
 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2086
 wb_writeback+0x7f3/0xb70 fs/fs-writeback.c:2197
 wb_check_background_flush fs/fs-writeback.c:2267 [inline]
 wb_do_writeback fs/fs-writeback.c:2355 [inline]
 wb_workfn+0x748/0xbe0 fs/fs-writeback.c:2382
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
6 locks held by kworker/u10:1/18384:
 #0: ffff88801eee1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
 #1: ffffc9000bbd7d10 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
 #2: ffff88814df7c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562
 #3: ffff88814df7eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x277/0x600 mm/page-writeback.c:2604
 #4: ffff888024088950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444
 #5: ffff88807e5f7530 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x46f/0x1400 fs/ext4/inode.c:810
2 locks held by getty/24049:
 #0: ffff88803110c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032102f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz.4.4169/25910:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf3f/0x1170 kernel/hung_task.c:495
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>