INFO: task kworker/u8:6:392 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6    state:D stack:20504 pid:392   tgid:392   ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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+0x1697/0x2c40 block/blk-mq.c:3188
 __submit_bio_noacct_mq block/blk-core.c:757 [inline]
 submit_bio_noacct_nocheck+0x2fe/0xb10 block/blk-core.c:791
 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline]
 ext4_io_submit fs/ext4/page-io.c:399 [inline]
 io_submit_add_bh fs/ext4/page-io.c:455 [inline]
 ext4_bio_write_folio+0x101a/0x18c0 fs/ext4/page-io.c:550
 mpage_process_page_bufs+0x6bd/0x8a0 fs/ext4/inode.c:2327
 mpage_prepare_extent_to_map+0xf8d/0x1880 fs/ext4/inode.c:2875
 ext4_do_writepages+0xc08/0x44a0 fs/ext4/inode.c:3023
 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3171
 do_writepages+0x338/0x560 mm/page-writeback.c:2562
 __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_old_data_flush fs/fs-writeback.c:2402 [inline]
 wb_do_writeback fs/fs-writeback.c:2481 [inline]
 wb_workfn+0xc92/0x10f0 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/sda1-8:4970 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jbd2/sda1-8     state:D stack:25288 pid:4970  tgid:4970  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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>
INFO: task syz-executor:5627 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21736 pid:5627  tgid:5627  ppid:5626   task_flags:0x440100 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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_bit_io include/linux/wait_bit.h:106 [inline]
 do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253
 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451
 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2741
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864
 do_page_mkwrite+0x147/0x310 mm/memory.c:3881
 wp_page_shared mm/memory.c:4285 [inline]
 do_wp_page+0x1a85/0x4b80 mm/memory.c:4508
 handle_pte_fault mm/memory.c:6681 [inline]
 __handle_mm_fault mm/memory.c:6806 [inline]
 handle_mm_fault+0x19c9/0x2f80 mm/memory.c:6973
 do_user_addr_fault+0xb35/0x1480 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f61d347dad6
RSP: 002b:00007ffe8f338210 EFLAGS: 00010202
RAX: 00007f61d14dc000 RBX: 00005555749a9d90 RCX: 0000000000000003
RDX: 000000000000196a RSI: 00005555749b2df8 RDI: 0000000000000008
RBP: 00007ffe8f338710 R08: 00005555749b2f90 R09: 00000000000000a1
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe8f338550
R13: 00007ffe8f338340 R14: 585858582e7a7973 R15: 00007ffe8f338290
 </TASK>
INFO: task syz.2.8719:2767 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.8719      state:D stack:25608 pid:2767  tgid:2767  ppid:28430  task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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_bit_io include/linux/wait_bit.h:106 [inline]
 do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253
 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451
 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2741
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864
 do_page_mkwrite+0x147/0x310 mm/memory.c:3881
 do_shared_fault mm/memory.c:6177 [inline]
 do_fault mm/memory.c:6239 [inline]
 do_pte_missing+0x70f/0x3570 mm/memory.c:4768
 handle_pte_fault mm/memory.c:6654 [inline]
 __handle_mm_fault mm/memory.c:6806 [inline]
 handle_mm_fault+0x1807/0x2f80 mm/memory.c:6973
 do_user_addr_fault+0xb35/0x1480 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f1129273ba9
RSP: 002b:00007ffd9faa58c0 EFLAGS: 00010202
RAX: 0000001b34a22000 RBX: ffffffff89c536e9 RCX: 0000001b34a21ff8
RDX: 0000001b3442421c RSI: 0000000000000008 RDI: 00007f112a155720
RBP: 000000000000012e R08: 00007f1129610000 R09: 00007f1129612000
R10: 0000000089c536ed R11: 0000000000000003 R12: 00007f1129626038
R13: 00000000000001c4 R14: ffffffff89c53341 R15: 00007f112a155720
 </TASK>
INFO: task syz.5.8720:2769 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.8720      state:D stack:25608 pid:2769  tgid:2769  ppid:1656   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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_bit_io include/linux/wait_bit.h:106 [inline]
 do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253
 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451
 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2741
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864
 do_page_mkwrite+0x147/0x310 mm/memory.c:3881
 do_shared_fault mm/memory.c:6177 [inline]
 do_fault mm/memory.c:6239 [inline]
 do_pte_missing+0x70f/0x3570 mm/memory.c:4768
 handle_pte_fault mm/memory.c:6654 [inline]
 __handle_mm_fault mm/memory.c:6806 [inline]
 handle_mm_fault+0x1807/0x2f80 mm/memory.c:6973
 do_user_addr_fault+0xb35/0x1480 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f34a4874332
RSP: 002b:00007fff4a9d42a0 EFLAGS: 00010202
RAX: 0000000000004008 RBX: 00007f34a5755720 RCX: 0000000000000000
RDX: 0000001b33720000 RSI: 0000000000000008 RDI: 00007f34a5755720
RBP: 00000000000003ae R08: 00007f34a4c10000 R09: 00007f34a4c26038
R10: 0000000000000003 R11: 0000000000000002 R12: ffffffff825b7289
R13: 00007f34a4c26038 R14: 0000000000000201 R15: ffffffffffffc000
 </TASK>
INFO: task syz.3.8721:2770 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.8721      state:D stack:25352 pid:2770  tgid:2770  ppid:5639   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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_bit_io include/linux/wait_bit.h:106 [inline]
 do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253
 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451
 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2741
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864
 do_page_mkwrite+0x147/0x310 mm/memory.c:3881
 do_shared_fault mm/memory.c:6177 [inline]
 do_fault mm/memory.c:6239 [inline]
 do_pte_missing+0x70f/0x3570 mm/memory.c:4768
 handle_pte_fault mm/memory.c:6654 [inline]
 __handle_mm_fault mm/memory.c:6806 [inline]
 handle_mm_fault+0x1807/0x2f80 mm/memory.c:6973
 do_user_addr_fault+0xb35/0x1480 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f17a5873ba9
RSP: 002b:00007ffd93137590 EFLAGS: 00010202
RAX: 0000001b2d524000 RBX: ffffffff825f06ea RCX: 0000001b2d523ff8
RDX: 00000000005ffde8 RSI: 00000000005ffde8 RDI: 00007f17a6755700
RBP: 0000000000000001 R08: 0000000000000000 R09: 00007f17a5c12000
R10: 00007f17a6755700 R11: 0000000000000000 R12: 00007f17a5c26038
R13: 0000000000000000 R14: ffffffff825f0f80 R15: 00007f17a6755720
 </TASK>
INFO: task syz.9.8722:2773 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L       syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.8722      state:D stack:26728 pid:2773  tgid:2773  ppid:20044  task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5830 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146
 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_bit_io include/linux/wait_bit.h:106 [inline]
 do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253
 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451
 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2741
 generic_update_time fs/inode.c:2253 [inline]
 touch_atime+0x568/0x670 fs/inode.c:2328
 file_accessed include/linux/fs.h:2281 [inline]
 ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919
 vfs_mmap_prepare include/linux/fs.h:2073 [inline]
 call_mmap_prepare mm/vma.c:2939 [inline]
 __mmap_region mm/vma.c:3056 [inline]
 mmap_region+0xef9/0x2840 mm/vma.c:3154
 do_mmap+0xe0a/0x1300 mm/mmap.c:573
 vm_mmap_pgoff+0x27a/0x520 mm/util.c:581
 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619
 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: 0033:0x7ffbdc79f2c2
RSP: 002b:00007fffb441c5e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000001b30864000 RCX: 00007ffbdc79f2c2
RDX: 0000000000000003 RSI: 00000000005c0000 RDI: 0000001b30864000
RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000
R10: 0000000000100001 R11: 0000000000000206 R12: 00000000000002d2
R13: 00000000000927c0 R14: 00000000000e1362 R15: 00007fffb441c8c0
 </TASK>

Showing all locks held in the system:
locks held by kworker/u8:1/14: 3, last CPU#0:
 #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #1: ffffc90000137c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90000137c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90000137c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #1: ffffc90000137c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #2: ffff88807a296258 (&devlink->lock_key#11){+.+.}-{4:4}, at: lock_timer_base kernel/time/timer.c:1005 [inline]
 #2: ffff88807a296258 (&devlink->lock_key#11){+.+.}-{4:4}, at: __mod_timer+0x1a9/0xed0 kernel/time/timer.c:1086
locks held by pr/ttyS0/35: 2, last CPU#1:
 #0: ffffffff90033f58 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff90033f58 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:493 [inline]
 #0: ffffffff90033f58 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
 #1: ffffffff9c200738 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9c200738 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/36: 1, last CPU#0:
 #0: ffffffff9015a4a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff9015a4a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff9015a4a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:6/392: 4, on CPU#1:
 #0: ffff8880216ec148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880216ec148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880216ec148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #0: ffff8880216ec148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #1: ffffc900036c7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900036c7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900036c7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #1: ffffc900036c7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #2: ffff88807fd360e8 (&type->s_umount_key#35){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:670
 #3: ffff88807fd14cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3170
locks held by klogd/4996: 1, last CPU#0:
 #0: ffffffff902b1c90 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:213 [inline]
 #0: ffffffff902b1c90 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:320
locks held by getty/5395: 2, on CPU#0:
 #0: ffff88807fcd30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5627: 3, on CPU#0:
 #0: ffff88807e80cbc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:337
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863
 #2: ffff88807fd34950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
locks held by syz.2.8719/2767: 3, on CPU#0:
 #0: ffff888078412448 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:337
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863
 #2: ffff88807fd34950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
locks held by syz.5.8720/2769: 3, on CPU#1:
 #0: ffff88807cdeed08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:337
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863
 #2: ffff88807fd34950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
locks held by syz.3.8721/2770: 3, on CPU#0:
 #0: ffff88805ee17308 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:337
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807fd36558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863
 #2: ffff88807fd34950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
locks held by syz.9.8722/2773: 3, on CPU#1:
 #0: ffff88803765d900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:551 [inline]
 #0: ffff88803765d900 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1ed/0x520 mm/util.c:579
 #1: ffff88807fd36460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2281 [inline]
 #1: ffff88807fd36460 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919
 #2: ffff88807fd34950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 Comm: khungtaskd Tainted: G             L       syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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: 35 Comm: pr/ttyS0 Tainted: G             L       syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:425
Code: e8 fe 0c 44 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ef 24 bb fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000ab78b8 EFLAGS: 00000002
RAX: 1ffffffff3840000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85850cb0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9c200760 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812350e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055663208e168 CR3: 000000000ff48000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:134 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
 wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2036
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3294 [inline]
 __serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3369
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
 serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3520
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
 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: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 0.829 msecs