INFO: task kworker/u8:0:12 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/u8:0 state:D stack:22168 pid:12 tgid:12 ppid:2 task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
io_schedule+0x8a/0xf0 kernel/sched/core.c:8190
bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:258
__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:106 [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+0x277/0x380 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x18f/0x910 fs/ext4/inode.c:6694
__ext4_ext_dirty+0x1b2/0x230 fs/ext4/extents.c:207
ext4_ext_insert_extent+0x11ff/0x4540 fs/ext4/extents.c:2210
ext4_ext_map_blocks+0x21f5/0x56d0 fs/ext4/extents.c:4490
ext4_map_create_blocks+0xec/0x5e0 fs/ext4/inode.c:630
ext4_map_blocks+0x46b/0xdd0 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+0x2282/0x3e80 fs/ext4/inode.c:2938
ext4_writepages+0x34a/0x750 fs/ext4/inode.c:3032
do_writepages+0x278/0x600 mm/page-writeback.c:2560
__writeback_single_inode+0x164/0x1560 fs/fs-writeback.c:1788
writeback_sb_inodes+0x766/0x1c50 fs/fs-writeback.c:2099
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2175
wb_writeback+0x6f6/0xb50 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+0x93f/0xc80 fs/fs-writeback.c:2497
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
process_scheduled_works kernel/workqueue.c:3479 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz-executor:5588 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:22560 pid:5588 tgid:5588 ppid:5587 task_flags:0x440100 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
io_schedule+0x8a/0xf0 kernel/sched/core.c:8190
bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:258
__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:106 [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+0x277/0x380 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x18f/0x910 fs/ext4/inode.c:6694
ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6731
__mark_inode_dirty+0x1f3/0x16e0 fs/fs-writeback.c:2729
generic_update_time fs/inode.c:2253 [inline]
file_update_time_flags+0x49c/0x520 fs/inode.c:2483
ext4_page_mkwrite+0x324/0x1860 fs/ext4/inode.c:6897
do_page_mkwrite+0x17a/0x440 mm/memory.c:3816
wp_page_shared mm/memory.c:4217 [inline]
do_wp_page+0x9ed/0x45c0 mm/memory.c:4440
handle_pte_fault mm/memory.c:6582 [inline]
__handle_mm_fault+0x1cd2/0x2f60 mm/memory.c:6707
handle_mm_fault+0x363/0xa20 mm/memory.c:6876
do_user_addr_fault+0x59c/0x12f0 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7effbfe701e3
RSP: 002b:00007ffc16e146a0 EFLAGS: 00010216
RAX: 00007effbadd5764 RBX: 00007ffc16e147d0 RCX: 0000000000000000
RDX: 00007effbadd5760 RSI: 0000000000000008 RDI: 00007ffc16e147d0
RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffc16e147b0 R11: 0000000000000000 R12: 0000000000000000
R13: 000000000002a89c R14: fffffffffffd5764 R15: 0000000000000000
INFO: task syz.3.672:7453 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.3.672 state:D stack:26728 pid:7453 tgid:7453 ppid:5606 task_flags:0x440040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
io_schedule+0x8a/0xf0 kernel/sched/core.c:8190
bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:258
__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:106 [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+0x277/0x380 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x18f/0x910 fs/ext4/inode.c:6694
ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6731
__mark_inode_dirty+0x1f3/0x16e0 fs/fs-writeback.c:2729
generic_update_time fs/inode.c:2253 [inline]
file_update_time_flags+0x49c/0x520 fs/inode.c:2483
ext4_page_mkwrite+0x324/0x1860 fs/ext4/inode.c:6897
do_page_mkwrite+0x17a/0x440 mm/memory.c:3816
do_shared_fault mm/memory.c:6076 [inline]
do_fault+0x659/0x1830 mm/memory.c:6138
do_pte_missing mm/memory.c:4700 [inline]
handle_pte_fault mm/memory.c:6558 [inline]
__handle_mm_fault+0x150b/0x2f60 mm/memory.c:6707
handle_mm_fault+0x363/0xa20 mm/memory.c:6876
do_user_addr_fault+0x59c/0x12f0 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7fd686272f32
RSP: 002b:00007ffcbdc65070 EFLAGS: 00010202
RAX: 0000000000006008 RBX: 00007fd687155720 RCX: 0000000000000000
RDX: 0000001b32f1e000 RSI: 0000000000000008 RDI: 00007fd687155720
RBP: 0000000000000581 R08: 00007fd686610000 R09: 00007fd686626038
R10: 0000000000000003 R11: 0000000000000003 R12: ffffffff8bcb4a32
R13: 00007fd686626038 R14: 0000000000000045 R15: ffffffffffffa000
INFO: task syz.1.673:7455 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.1.673 state:D stack:27128 pid:7455 tgid:7455 ppid:5600 task_flags:0x440040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
io_schedule+0x8a/0xf0 kernel/sched/core.c:8190
bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:258
__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:106 [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+0x277/0x380 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x18f/0x910 fs/ext4/inode.c:6694
ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6731
__mark_inode_dirty+0x1f3/0x16e0 fs/fs-writeback.c:2729
generic_update_time fs/inode.c:2253 [inline]
file_update_time_flags+0x49c/0x520 fs/inode.c:2483
ext4_page_mkwrite+0x324/0x1860 fs/ext4/inode.c:6897
do_page_mkwrite+0x17a/0x440 mm/memory.c:3816
do_shared_fault mm/memory.c:6076 [inline]
do_fault+0x659/0x1830 mm/memory.c:6138
do_pte_missing mm/memory.c:4700 [inline]
handle_pte_fault mm/memory.c:6558 [inline]
__handle_mm_fault+0x150b/0x2f60 mm/memory.c:6707
handle_mm_fault+0x363/0xa20 mm/memory.c:6876
do_user_addr_fault+0x59c/0x12f0 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7fe3e7472f32
RSP: 002b:00007fffddf69ee0 EFLAGS: 00010202
RAX: 0000000000005008 RBX: 00007fe3e8355720 RCX: 0000000000000000
RDX: 0000001b32d1f000 RSI: 0000000000000008 RDI: 00007fe3e8355720
RBP: 00000000000012a1 R08: 00007fe3e7810000 R09: 00007fe3e7826038
R10: 0000000000000003 R11: 0000000000000003 R12: ffffffff8bca5cae
R13: 00007fe3e7826038 R14: 0000000000000155 R15: ffffffffffffb000
Showing all locks held in the system:
locks held by kworker/u8:0/12: 6, on CPU#0:
#0: ffff88802128f940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90000117d08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff8880374e40e8 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x21/0xf0 fs/super.c:688
#3: ffff8880374e2c98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2560
#4: ffff8880374e0938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfa7/0x1390 fs/jbd2/transaction.c:444
#5: ffff888074ccaf68 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0x45a/0xdd0 fs/ext4/inode.c:822
locks held by pr/ttyS0/16: 2, last CPU#1:
#0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
#1: ffffffff9bc60c78 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9bc60c78 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6837
locks held by kworker/u8:11/314: 3, last CPU#1:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000310fd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802665b258 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834
locks held by getty/5357: 2, on CPU#0:
#0: ffff888036f750a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by syz-executor/5588: 3, on CPU#1:
#0: ffff888073323a88 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
#1: ffff8880374e4558 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3816
#2: ffff8880374e0938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfa7/0x1390 fs/jbd2/transaction.c:444
locks held by syz.3.672/7453: 3, on CPU#1:
#0: ffff88807d9d1bc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
#1: ffff8880374e4558 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3816
#2: ffff8880374e0938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfa7/0x1390 fs/jbd2/transaction.c:444
locks held by syz.1.673/7455: 3, on CPU#1:
#0: ffff8880769fbbc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
#1: ffff8880374e4558 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3816
#2: ffff8880374e0938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfa7/0x1390 fs/jbd2/transaction.c:444
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__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:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+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+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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 08/05/2026
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 1f 5c fc 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 48 32 cf fc eb a2 e8 d1 32
RSP: 0018:ffffc90000157958 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff85afd0d0 RDI: ffffffff9bc60ca0
RBP: ffffffff9bc60c60 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 205d323354202020 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff378c1e9 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888123c64000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e3c50a3660 CR3: 000000000eb96000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2013
serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3270
__serial8250_console_fifo_write+0xa5/0x290 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+0xf46/0x1330 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245