INFO: task kworker/u8:5:145 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:23376 pid:145   tgid:145   ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6855
 __schedule_loop kernel/sched/core.c:6937 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6952
 io_schedule+0xbf/0x130 kernel/sched/core.c:7784
 rq_qos_wait+0x22f/0x340 block/blk-rq-qos.c:307
 __wbt_wait block/blk-wbt.c:596 [inline]
 wbt_wait+0x1b8/0x3a0 block/blk-wbt.c:656
 __rq_qos_throttle+0x56/0xa0 block/blk-rq-qos.c:66
 rq_qos_throttle block/blk-rq-qos.h:168 [inline]
 rq_qos_throttle block/blk-rq-qos.h:163 [inline]
 blk_mq_get_new_requests block/blk-mq.c:3042 [inline]
 blk_mq_submit_bio+0x2274/0x2bf0 block/blk-mq.c:3193
 __submit_bio+0x3cf/0x690 block/blk-core.c:637
 __submit_bio_noacct_mq block/blk-core.c:724 [inline]
 submit_bio_noacct_nocheck+0x53d/0xbe0 block/blk-core.c:755
 submit_bio_noacct+0x5bd/0x1f40 block/blk-core.c:879
 ext4_io_submit fs/ext4/page-io.c:404 [inline]
 io_submit_add_bh fs/ext4/page-io.c:445 [inline]
 ext4_bio_write_folio+0x756/0x1dc0 fs/ext4/page-io.c:589
 mpage_process_page_bufs+0x47c/0x8d0 fs/ext4/inode.c:2190
 mpage_prepare_extent_to_map+0x765/0x14b0 fs/ext4/inode.c:2732
 ext4_do_writepages+0xa11/0x3c70 fs/ext4/inode.c:2873
 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3021
 do_writepages+0x27a/0x600 mm/page-writeback.c:2598
 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x795/0x1de0 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107
 wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218
 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
 wb_do_writeback fs/fs-writeback.c:2375 [inline]
 wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403
 process_one_work+0x9ba/0x1b20 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+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
INFO: task syz.0.23:6490 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.23        state:D stack:28824 pid:6490  tgid:6490  ppid:6345   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6855
 __schedule_loop kernel/sched/core.c:6937 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6952
 io_schedule+0xbf/0x130 kernel/sched/core.c:7784
 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+0x910/0x12f0 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_reserve_inode_write+0x1be/0x340 fs/ext4/inode.c:6301
 __ext4_mark_inode_dirty+0x197/0x840 fs/ext4/inode.c:6476
 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6513
 __mark_inode_dirty+0x1f7/0x1670 fs/fs-writeback.c:2587
 generic_update_time+0xcf/0xf0 fs/inode.c:2154
 inode_update_time fs/inode.c:2167 [inline]
 file_update_time_flags+0x410/0x520 fs/inode.c:2394
 ext4_page_mkwrite+0x33d/0x1880 fs/ext4/inode.c:6679
 do_page_mkwrite+0x174/0x380 mm/memory.c:3489
 do_shared_fault mm/memory.c:5792 [inline]
 do_fault mm/memory.c:5854 [inline]
 do_pte_missing+0x29c/0x4000 mm/memory.c:4362
 handle_pte_fault mm/memory.c:6234 [inline]
 __handle_mm_fault+0x154b/0x2ad0 mm/memory.c:6366
 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6535
 do_user_addr_fault+0x423/0xda0 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f72ffe605f1
RSP: 002b:00007ffece2d94b0 EFLAGS: 00010202
RAX: 0000001b30260000 RBX: 00007f7300ce5720 RCX: 0000000000000003
RDX: 0000001b3025ffff RSI: 0000000000000008 RDI: 00007f7300ce5720
RBP: 00007f73001b6038 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f7300ce5700 R11: 0000000000000000 R12: 00000000fffffc03
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e1c9420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e1c9420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e1c9420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:5/145:
 #0: ffff888140ac5948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3238
 #1: ffffc90002ec7c90 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3239
 #2: ffff8880345620e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:563
 #3: ffff888034564b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x27a/0x600 mm/page-writeback.c:2598
5 locks held by kworker/u8:7/2050:
2 locks held by klogd/5197:
 #0: ffff8880b853ab98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:639
 #1: ffff8880b8524508 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline]
 #1: ffff8880b8524508 (psi_seq){-.-.}-{0:0}, at: __schedule+0x19b1/0x6150 kernel/sched/core.c:6849
2 locks held by getty/5600:
 #0: ffff8880348d30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
3 locks held by syz.0.23/6490:
 #0: ffff88807e871a88 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x117/0x580 mm/mmap_lock.c:238
 #1: ffff888034562518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x174/0x380 mm/memory.c:3489
 #2: ffff888034566950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444
3 locks held by syz-executor/6493:
 #0: ffff888034562420 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10d/0x400 fs/namei.c:4872
 #1: ffff888075d259f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
 #1: ffff888075d259f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
 #1: ffff888075d259f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
 #1: ffff888075d259f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1c0/0x400 fs/namei.c:4879
 #2: ffff888034566950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444

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

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 10/25/2025
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+0xf14/0x1140 kernel/hung_task.c:495
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </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 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: a6 58 02 e9 d3 2f 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 73 71 0e 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:ffffc90000197de8 EFLAGS: 000002c2
RAX: 00000000000c9bf3 RBX: 0000000000000001 RCX: ffffffff8b5be6f9
RDX: 0000000000000000 RSI: ffffffff8d89fdde RDI: ffffffff8bd1d700
RBP: ffffed1003a5bb70 R08: 0000000000000001 R09: ffffed10170a672d
R10: ffff8880b853396b R11: 00000000fb268dbe R12: 0000000000000001
R13: ffff88801d2ddb80 R14: ffffffff906604d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124ca3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c12b6eba38 CR3: 000000000df84000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x38d/0x510 kernel/sched/idle.c:332
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>