INFO: task kworker/u8:8:1024 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/u8:8    state:D stack:21384 pid:1024  tgid:1024  ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5584 [inline]
 __schedule+0x1b47/0x5b40 kernel/sched/core.c:7387
 __schedule_loop kernel/sched/core.c:7464 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7479
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8151
 rq_qos_wait+0x266/0x360 block/blk-rq-qos.c:307
 __wbt_wait block/blk-wbt.c:598 [inline]
 wbt_wait+0x326/0x550 block/blk-wbt.c:658
 __rq_qos_throttle+0x6b/0xb0 block/blk-rq-qos.c:66
 rq_qos_throttle block/blk-rq-qos.h:164 [inline]
 blk_mq_get_new_requests block/blk-mq.c:3046 [inline]
 blk_mq_submit_bio+0x165d/0x2bb0 block/blk-mq.c:3182
 __submit_bio_noacct_mq block/blk-core.c:757 [inline]
 submit_bio_noacct_nocheck+0x34e/0xa40 block/blk-core.c:791
 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline]
 ext4_io_submit+0x11b/0x190 fs/ext4/page-io.c:396
 ext4_do_writepages+0x11e1/0x4770 fs/ext4/inode.c:2958
 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3032
 do_writepages+0x338/0x560 mm/page-writeback.c:2560
 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1800
 writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2111
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2187
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2298
 wb_check_background_flush fs/fs-writeback.c:2368 [inline]
 wb_do_writeback fs/fs-writeback.c:2482 [inline]
 wb_workfn+0xd5b/0x10f0 fs/fs-writeback.c:2509
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 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>
INFO: task jbd2/sda1-8:4942 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:4942  tgid:4942  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5584 [inline]
 __schedule+0x1b47/0x5b40 kernel/sched/core.c:7387
 __schedule_loop kernel/sched/core.c:7464 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7479
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8151
 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258
 __wait_on_bit+0xac/0x300 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:476 [inline]
 jbd2_journal_commit_transaction+0x2f6e/0x5c80 fs/jbd2/commit.c:834
 kjournald2+0x3bc/0x740 fs/jbd2/journal.c:200
 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>

Showing all locks held in the system:
locks held by khungtaskd/33: 1, last CPU#0:
 #0: ffffffff8f15a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8f15a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8f15a260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:8/1024: 4, on CPU#1:
 #0: ffff888020696148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888020696148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888020696148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #0: ffff888020696148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #1: ffffc90004e47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90004e47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90004e47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #1: ffffc90004e47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #2: ffff88803696e0e8 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:670
 #3: ffff88803696cc98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3031
locks held by getty/5371: 2, on CPU#0:
 #0: ffff8880369130a0 (&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 sshd-session/5649: 1, last CPU#1:
 #0: ffff8880358a0f60 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
 #0: ffff8880358a0f60 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1452

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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:377 [inline]
 watchdog+0x1073/0x10f0 kernel/hung_task.c:598
 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: 5650 Comm: strace-static-x Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:entry_SYSCALL_64+0x4/0x2b arch/x86/entry/entry_64.S:91
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa <0f> 01 f8 65 48 89 25 85 6f dd 12 66 90 0f 20 dc 0f 1f 44 00 00 48
RSP: 0018:00007ffdac32efb0 EFLAGS: 00000002
RAX: 000000000000003d RBX: 0000000000000001 RCX: 0000000000518762
RDX: 0000000040000001 RSI: 00007ffdac32f010 RDI: ffffffffffffffff
RBP: 0000000010c90140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000020df
R13: 0000000000676170 R14: 00007ffdac32f010 R15: 0000000010c94770
FS:  0000000010c8e440(0000) GS:ffff888124732000(0000) knlGS:ffff888124732000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f926b4a17f0 CR3: 00000000783ee000 CR4: 00000000003526f0
Call Trace: