INFO: task kworker/u8:2:39 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:kworker/u8:2    state:D stack:22472 pid:39    tgid:39    ppid:2      task_flags:0x4248160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 io_schedule+0x80/0xe0 kernel/sched/core.c:8220
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258
 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:106 [inline]
 do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249
 ext4_mb_mark_context+0x171/0xec0 fs/ext4/mballoc.c:4112
 ext4_mb_mark_diskspace_used+0x338/0x760 fs/ext4/mballoc.c:4241
 ext4_mb_new_blocks+0x106f/0x4540 fs/ext4/mballoc.c:6329
 ext4_ext_map_blocks+0x13f1/0x5680 fs/ext4/extents.c:4469
 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:630
 ext4_map_blocks+0x791/0x12c0 fs/ext4/inode.c:823
 mpage_map_one_extent fs/ext4/inode.c:2379 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2469 [inline]
 ext4_do_writepages+0x239b/0x4770 fs/ext4/inode.c:2938
 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3032
 do_writepages+0x338/0x560 mm/page-writeback.c:2560
 __writeback_single_inode+0x136/0x1230 fs/fs-writeback.c:1803
 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2114
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2190
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2301
 wb_check_old_data_flush fs/fs-writeback.c:2405 [inline]
 wb_do_writeback fs/fs-writeback.c:2484 [inline]
 wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2512
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/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>
INFO: task jbd2/sda1-8:4913 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:jbd2/sda1-8     state:D stack:26280 pid:4913  tgid:4913  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 io_schedule+0x80/0xe0 kernel/sched/core.c:8220
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258
 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67
 wait_on_buffer include/linux/buffer_head.h:418 [inline]
 jbd2_journal_commit_transaction+0x2f26/0x5ba0 fs/jbd2/commit.c:834
 kjournald2+0x3bc/0x750 fs/jbd2/journal.c:200
 kthread+0x38b/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>

Showing all locks held in the system:
locks held by khungtaskd/38: 1, last CPU#0:
 #0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:2/39: 7, on CPU#1:
 #0: ffff88801f2dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801f2dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801f2dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801f2dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff88803529e0e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:670
 #3: ffff888035998d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
 #3: ffff888035998d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1887 [inline]
 #3: ffff888035998d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3031
 #4: ffff88803529abb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
 #5: ffff88804055e810 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0x77d/0x12c0 fs/ext4/inode.c:822
 #6: ffffe8ffffd345c0 (&lg->lg_mutex){+.+.}-{4:4}, at: ext4_mb_group_or_file fs/ext4/mballoc.c:5880 [inline]
 #6: ffffe8ffffd345c0 (&lg->lg_mutex){+.+.}-{4:4}, at: ext4_mb_initialize_context+0x854/0xc20 fs/ext4/mballoc.c:5924
locks held by getty/5338: 2, on CPU#0:
 #0: ffff8880352b30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900044cb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211

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

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 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/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: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:decay_load kernel/sched/pelt.c:54 [inline]
RIP: 0010:accumulate_sum kernel/sched/pelt.c:118 [inline]
RIP: 0010:___update_load_sum kernel/sched/pelt.c:227 [inline]
RIP: 0010:__update_load_avg_se+0x2c9/0xbd0 kernel/sched/pelt.c:309
Code: fc ff df 4c 8b 3f 48 81 fd 00 80 00 00 0f 83 04 05 00 00 4c 8b 4c 24 10 4c 89 c8 4c 8d 24 85 40 9d 6c 8b 4c 89 e0 48 c1 e8 03 <0f> b6 04 30 84 c0 0f 85 83 06 00 00 41 8b 04 24 49 f7 e7 49 89 d4
RSP: 0018:ffffc90000a3f8c0 EFLAGS: 00000807
RAX: 1ffffffff16d93ac RBX: ffff888037c85e40 RCX: 7ffffffffffffc00
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff888037c85f50
RBP: 00000000000026e2 R08: ffffffff8fb22a7f R09: 0000000000000009
R10: dffffc0000000000 R11: fffffbfff1f64550 R12: ffffffff8b6c9d64
R13: 00000000000024a3 R14: 1ffff11006f90bea R15: 00000000005c63a1
FS:  0000000000000000(0000) GS:ffff888125cc4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 00000000115a4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 update_load_avg+0x1a8/0x1920 kernel/sched/fair.c:5870
 enqueue_entity kernel/sched/fair.c:6340 [inline]
 enqueue_hierarchy kernel/sched/fair.c:7952 [inline]
 enqueue_task_fair+0x674/0x1b60 kernel/sched/fair.c:8035
 enqueue_task+0x75/0x410 kernel/sched/core.c:2194
 activate_task kernel/sched/core.c:2234 [inline]
 ttwu_do_activate+0x1c8/0x640 kernel/sched/core.c:3847
 ttwu_queue kernel/sched/core.c:4100 [inline]
 try_to_wake_up+0x7b1/0x1430 kernel/sched/core.c:4438
 hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:2330
 __run_hrtimer kernel/time/hrtimer.c:2074 [inline]
 __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2131
 hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2148
 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 run_ktimerd+0x6a/0x100 kernel/softirq.c:1174
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 kthread+0x38b/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>