INFO: task kworker/u8:1:13 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/u8:1    state:D stack:24192 pid:13    tgid:13    ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8154
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x836/0x11e0 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
 ext4_mb_mark_context+0x1df/0xdb0 fs/ext4/mballoc.c:4124
 ext4_mb_mark_diskspace_used+0x472/0x800 fs/ext4/mballoc.c:4240
 ext4_mb_new_blocks+0x92a/0x4c20 fs/ext4/mballoc.c:6328
 ext4_ext_map_blocks+0x1c66/0x59a0 fs/ext4/extents.c:4461
 ext4_map_create_blocks+0xec/0x5e0 fs/ext4/inode.c:631
 ext4_map_blocks+0x46b/0xd30 fs/ext4/inode.c:824
 mpage_map_one_extent fs/ext4/inode.c:2397 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2491 [inline]
 ext4_do_writepages+0x224c/0x3ed0 fs/ext4/inode.c:2949
 ext4_writepages+0x347/0x750 fs/ext4/inode.c:3043
 do_writepages+0x278/0x600 mm/page-writeback.c:2571
 __writeback_single_inode+0x164/0x1300 fs/fs-writeback.c:1787
 writeback_sb_inodes+0x766/0x1c50 fs/fs-writeback.c:2079
 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2155
 wb_writeback+0x6f6/0xb50 fs/fs-writeback.c:2266
 wb_check_old_data_flush fs/fs-writeback.c:2370 [inline]
 wb_do_writeback fs/fs-writeback.c:2449 [inline]
 wb_workfn+0x93f/0xc80 fs/fs-writeback.c:2477
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task jbd2/sda1-8:4924 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:27160 pid:4924  tgid:4924  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8154
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 __wait_on_buffer+0x64/0x70 fs/buffer.c:118
 wait_on_buffer include/linux/buffer_head.h:422 [inline]
 jbd2_journal_commit_transaction+0x37ef/0x6700 fs/jbd2/commit.c:834
 kjournald2+0x200/0x760 fs/jbd2/journal.c:199
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 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:
7 locks held by kworker/u8:1/13:
 #0: ffff888020ecc140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
 #1: ffffc90000127d08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
 #2: ffff888037f3a0d8 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:566
 #3: ffff888037f38c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2571
 #4: ffff888037f46938 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
 #5: ffff8880751394d8 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0x45a/0xd30 fs/ext4/inode.c:823
 #6: ffffe8ffffd27640 (&lg->lg_mutex){+.+.}-{4:4}, at: ext4_mb_group_or_file fs/ext4/mballoc.c:5879 [inline]
 #6: ffffe8ffffd27640 (&lg->lg_mutex){+.+.}-{4:4}, at: ext4_mb_initialize_context+0x819/0xde0 fs/ext4/mballoc.c:5923
1 lock held by khungtaskd/30:
 #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
1 lock held by klogd/4951:
 #0: ffff8880b843b520 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:667
2 locks held by getty/5352:
 #0: ffff8880377f70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 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+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 55 8c 02 e9 83 4b 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 cf 10 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197e00 EFLAGS: 00000242
RAX: 0000000000267bf7 RBX: ffff88801eac2540 RCX: ffffffff8bbad335
RDX: 0000000000000000 RSI: ffffffff8e1a9419 RDI: ffffffff8c400480
RBP: ffffed1003d584a8 R08: 0000000000000001 R09: ffffed10170a678d
R10: ffff8880b8533c6b R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f96a46e83e0 CR3: 00000000707b1000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>