INFO: task kworker/u8:12:1824 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/u8:12   state:D stack:23200 pid:1824  tgid:1824  ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 io_schedule+0x80/0xe0 kernel/sched/core.c:8213
 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+0x325/0xec0 fs/ext4/mballoc.c:4125
 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:1788
 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2099
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2175
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2286
 wb_check_old_data_flush fs/fs-writeback.c:2390 [inline]
 wb_do_writeback fs/fs-writeback.c:2469 [inline]
 wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2497
 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/sda1-8:4917 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:25096 pid:4917  tgid:4917  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 io_schedule+0x80/0xe0 kernel/sched/core.c:8213
 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: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:12/1824: 6, on CPU#0:
 #0: ffff88801f287138 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801f287138 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801f287138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801f287138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000736fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000736fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000736fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000736fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff8880368780e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:674
 #3: ffff88803688cd98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
 #3: ffff88803688cd98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1887 [inline]
 #3: ffff88803688cd98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3031
 #4: ffff888036894bb0 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
 #5: ffff88803d8bc638 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0x77d/0x12c0 fs/ext4/inode.c:822
locks held by getty/5343: 2, on CPU#1:
 #0: ffff888035e990a0 (&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: 5622 Comm: strace-static-x Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:mmdrop_sched include/linux/sched/mm.h:77 [inline]
RIP: 0010:mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
RIP: 0010:finish_task_switch+0x4fa/0xc60 kernel/sched/core.c:5408
Code: 42 0f b6 04 30 84 c0 0f 85 e5 03 00 00 f7 03 20 00 00 00 0f 85 3a 02 00 00 4c 89 ff be 04 00 00 00 e8 0a cc 9c 00 f0 41 ff 0f <75> 16 49 81 c7 18 0c 00 00 4c 89 ff 48 c7 c6 30 af 96 81 e8 5e 79
RSP: 0018:ffffc90004a178c0 EFLAGS: 00000202
RAX: 1ffff1100701c401 RBX: ffff8880380e1f6c RCX: ffffffff8195bf66
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888037fcde80
RBP: ffffc90004a17910 R08: ffff888037fcde83 R09: 1ffff11006ff9bd0
R10: dffffc0000000000 R11: ffffed1006ff9bd1 R12: ffff8880380e2500
R13: ffff8880380e1f40 R14: dffffc0000000000 R15: ffff888037fcde80
FS:  0000000035cdd440(0000) GS:ffff888125cc8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555769ab6d0 CR3: 000000003fff6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5529 [inline]
 __schedule+0x16e1/0x5700 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 schedule_hrtimeout_range_clock+0x15b/0x330 kernel/time/sleep_timeout.c:216
 wait_task_inactive+0x4e1/0x800 kernel/sched/core.c:2443
 ptrace_check_attach+0x180/0x370 kernel/ptrace.c:280
 __do_sys_ptrace kernel/ptrace.c:1435 [inline]
 __se_sys_ptrace+0x12c/0x3a0 kernel/ptrace.c:1413
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x4ebd9b
Code: 8d 44 24 70 41 83 f8 03 c7 44 24 10 08 00 00 00 48 89 44 24 18 48 8d 44 24 30 4c 0f 43 d1 48 89 44 24 20 b8 65 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3d 48 85 c0 78 06 41 83 f8 02 76 1a 48 8b 54
RSP: 002b:00007fff0925ea70 EFLAGS: 00000206 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 0000000035cdf130 RCX: 00000000004ebd9b
RDX: 0000000000000058 RSI: 0000000000002790 RDI: 000000000000420e
RBP: 00007fff0925eb90 R08: 000000000000420d R09: 0000000000000000
R10: 000000000069b3c0 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000676170 R14: 0000000000000018 R15: 0000000035ce4770
 </TASK>