INFO: task jbd2/sda1-8:4946 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:25144 pid:4946  tgid:4946  ppid:2     
task:jbd2/sda1-8     state:D stack:25144 pid:4946  tgid:4946  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:418 [inline]
 jbd2_journal_commit_transaction+0x2f1d/0x5b70 fs/jbd2/commit.c:834
 kjournald2+0x3bc/0x750 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:5605 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:22312 pid:5605  tgid:5605  ppid:5604   task_flags:0x440100 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:105 [inline]
 do_get_write_access+0x662/0x1070 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_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6897
 do_page_mkwrite+0x147/0x310 mm/memory.c:3816
 wp_page_shared mm/memory.c:4217 [inline]
 do_wp_page+0x1a9c/0x4b80 mm/memory.c:4440
 handle_pte_fault mm/memory.c:6583 [inline]
 __handle_mm_fault mm/memory.c:6708 [inline]
 handle_mm_fault+0x15d7/0x3750 mm/memory.c:6877
 do_user_addr_fault+0xa4f/0x1340 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: 0033:0x7f8bd3270163
RSP: 002b:00007ffe17c04b90 EFLAGS: 00010202
RAX: 00007f8bce000000 RBX: 00007ffe17c04cc0 RCX: 00000000003ffde8
RDX: 00007f8bcdfffffc RSI: 0000000000000008 RDI: 00007ffe17c04cc0
RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffe17c04ca0 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task syz.8.475:8593 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.8.475       state:D stack:25608 pid:8593  tgid:8593  ppid:6824   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:105 [inline]
 do_get_write_access+0x662/0x1070 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_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6897
 do_page_mkwrite+0x147/0x310 mm/memory.c:3816
 do_shared_fault mm/memory.c:6077 [inline]
 do_fault mm/memory.c:6139 [inline]
 do_pte_missing+0x757/0x34b0 mm/memory.c:4700
 handle_pte_fault mm/memory.c:6559 [inline]
 __handle_mm_fault mm/memory.c:6708 [inline]
 handle_mm_fault+0x1a53/0x3750 mm/memory.c:6877
 do_user_addr_fault+0xa4f/0x1340 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: 0033:0x7faae4272789
RSP: 002b:00007ffe0706c8f0 EFLAGS: 00010202
RAX: 0000001b2f724000 RBX: 0000000000000000 RCX: 00000000003ffde8
RDX: 0000001b2f723ffc RSI: 00000000003ffde8 RDI: 00007faae5155700
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007faae4612000
R10: 00007faae5155700 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000114e0 R14: ffffffff816d5dee R15: 00007faae5155720
 </TASK>
INFO: task syz.6.486:8644 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.6.486       state:D stack:25608 pid:8644  tgid:8644  ppid:7124   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:105 [inline]
 do_get_write_access+0x662/0x1070 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_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6897
 do_page_mkwrite+0x147/0x310 mm/memory.c:3816
 do_shared_fault mm/memory.c:6077 [inline]
 do_fault mm/memory.c:6139 [inline]
 do_pte_missing+0x757/0x34b0 mm/memory.c:4700
 handle_pte_fault mm/memory.c:6559 [inline]
 __handle_mm_fault mm/memory.c:6708 [inline]
 handle_mm_fault+0x1a53/0x3750 mm/memory.c:6877
 do_user_addr_fault+0xa4f/0x1340 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: 0033:0x7f07492667f1
RSP: 002b:00007fff5fb1a680 EFLAGS: 00010202
RAX: 0000001b31f64000 RBX: 0000000000000000 RCX: 000000000003fde8
RDX: 0000001b31f63fff RSI: 0000000000000008 RDI: 00007f074a155720
RBP: 00007f074a155720 R08: 0000000000000000 R09: 00007f0749626128
R10: 00007f074a155700 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
 </TASK>
INFO: task syz.9.487:8647 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.9.487       state:D stack:26952 pid:8647  tgid:8647  ppid:6829   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:105 [inline]
 do_get_write_access+0x662/0x1070 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_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
 generic_update_time fs/inode.c:2253 [inline]
 touch_atime+0x568/0x670 fs/inode.c:2328
 file_accessed include/linux/fs.h:2277 [inline]
 ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901
 vfs_mmap_prepare include/linux/fs.h:2069 [inline]
 call_mmap_prepare mm/vma.c:2776 [inline]
 __mmap_region mm/vma.c:2863 [inline]
 mmap_region+0xe8a/0x2240 mm/vma.c:2964
 do_mmap+0xe0a/0x1300 mm/mmap.c:573
 vm_mmap_pgoff+0x272/0x4e0 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: 0033:0x7f180df9de42
RSP: 002b:00007fff5061fe88 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000001b2f864000 RCX: 00007f180df9de42
RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b2f864000
RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000
R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000003b
R13: 00000000000927c0 R14: 0000000000044de2 R15: 00007fff50620160
 </TASK>
INFO: task syz.5.489:8651 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.5.489       state:D stack:28200 pid:8651  tgid:8651  ppid:6072   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:105 [inline]
 do_get_write_access+0x662/0x1070 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_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
 generic_update_time fs/inode.c:2253 [inline]
 file_update_time_flags+0x399/0x440 fs/inode.c:2483
 ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6897
 do_page_mkwrite+0x147/0x310 mm/memory.c:3816
 do_shared_fault mm/memory.c:6077 [inline]
 do_fault mm/memory.c:6139 [inline]
 do_pte_missing+0x757/0x34b0 mm/memory.c:4700
 handle_pte_fault mm/memory.c:6559 [inline]
 __handle_mm_fault mm/memory.c:6708 [inline]
 handle_mm_fault+0x1a53/0x3750 mm/memory.c:6877
 do_user_addr_fault+0xa4f/0x1340 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: 0033:0x7f486326ba23
RSP: 002b:00007ffc5ab48940 EFLAGS: 00010246
RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000001b2f524000 RSI: 0000000000040000 RDI: 00007f48635e0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc5ab48bd0
 </TASK>
INFO: task syz.7.488:8652 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.7.488       state:D stack:27256 pid:8652  tgid:8652  ppid:6819   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __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:105 [inline]
 do_get_write_access+0x662/0x1070 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_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
 generic_update_time fs/inode.c:2253 [inline]
 touch_atime+0x568/0x670 fs/inode.c:2328
 file_accessed include/linux/fs.h:2277 [inline]
 ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901
 vfs_mmap_prepare include/linux/fs.h:2069 [inline]
 call_mmap_prepare mm/vma.c:2776 [inline]
 __mmap_region mm/vma.c:2863 [inline]
 mmap_region+0xe8a/0x2240 mm/vma.c:2964
 do_mmap+0xe0a/0x1300 mm/mmap.c:573
 vm_mmap_pgoff+0x272/0x4e0 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: 0033:0x7fd764f9de42
RSP: 002b:00007fff9ef9a268 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000001b2ee64000 RCX: 00007fd764f9de42
RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b2ee64000
RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000
R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000002b
R13: 00000000000927c0 R14: 0000000000044e47 R15: 00007fff9ef9a540
 </TASK>

Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#1:
 #0: ffffffff8ec36638 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8ec36638 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #0: ffffffff8ec36638 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
 #1: ffffffff9ad12b98 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9ad12b98 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/31: 1, last CPU#0:
 #0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by klogd/4973: 2, last CPU#0:
 #0: ffffffff8eea4c30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
 #0: ffffffff8eea4c30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:305
 #1: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #1: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by getty/5375: 2, on CPU#0:
 #0: ffff88807ff730a0 (&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 syz-executor/5605: 3, on CPU#1:
 #0: ffff8880359d3948 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1140 fs/ext4/inode.c:6896
 #2: ffff88807ffe8938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.8.475/8593: 3, on CPU#0:
 #0: ffff888069b8a448 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1140 fs/ext4/inode.c:6896
 #2: ffff88807ffe8938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.6.486/8644: 3, on CPU#0:
 #0: ffff88802866e6c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1140 fs/ext4/inode.c:6896
 #2: ffff88807ffe8938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.9.487/8647: 3, on CPU#1:
 #0: ffff88807e6da9f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #0: ffff88807e6da9f8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
 #1: ffff88807ffec460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2277 [inline]
 #1: ffff88807ffec460 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901
 #2: ffff88807ffe8938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.5.489/8651: 3, on CPU#0:
 #0: ffff88805a23ebc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff88807ffec558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1140 fs/ext4/inode.c:6896
 #2: ffff88807ffe8938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.7.488/8652: 3, on CPU#1:
 #0: ffff88807e6de9b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #0: ffff88807e6de9b8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
 #1: ffff88807ffec460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2277 [inline]
 #1: ffff88807ffec460 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901
 #2: ffff88807ffe8938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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/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: 16 Comm: pr/ttyS0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 ee 81 59 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 1f fc c7 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:ffffc900001578b8 EFLAGS: 00000002
RAX: 1ffffffff35a2500 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff856e3af0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9ad12bc0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124df8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a697fb0660 CR3: 000000000eb48000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:128 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
 wait_for_lsr+0xbc/0x2f0 drivers/tty/serial/8250/8250_port.c:2013
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
 __serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3345
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
 serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x679/0x880 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>