INFO: task kworker/u8:0:13 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/u8:0 state:D stack:22688 pid:13 tgid:13 ppid:2 task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
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_mb_mark_context+0x171/0xec0 fs/ext4/mballoc.c:4110
ext4_mb_mark_diskspace_used+0x338/0x760 fs/ext4/mballoc.c:4239
ext4_mb_new_blocks+0x1062/0x4520 fs/ext4/mballoc.c:6327
ext4_ext_map_blocks+0x1427/0x5480 fs/ext4/extents.c:4469
ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:697
ext4_map_blocks+0xe8e/0x1c60 fs/ext4/inode.c:942
mpage_map_one_extent fs/ext4/inode.c:2505 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2601 [inline]
ext4_do_writepages+0x1978/0x44a0 fs/ext4/inode.c:3077
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:1809
writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2120
__writeback_inodes_wb+0x114/0x250 fs/fs-writeback.c:2196
wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2307
wb_check_old_data_flush fs/fs-writeback.c:2411 [inline]
wb_do_writeback fs/fs-writeback.c:2490 [inline]
wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2518
process_one_work kernel/workqueue.c:3505 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3588
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3669
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
INFO: task jbd2/sda1-8:4968 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:26280 pid:4968 tgid:4968 ppid:2 task_flags:0x240040 flags:0x00080000
Call Trace:
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
Showing all locks held in the system:
locks held by kworker/u8:0/13: 7, on CPU#0:
#0: ffff8880216b6150 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8880216b6150 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8880216b6150 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline]
#0: ffff8880216b6150 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588
#2: ffff888037dc6100 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:642
#3: ffff888037cd4cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3170
#4: ffff888037dc4950 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
#5: ffff888076990218 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0xacb/0x1c60 fs/ext4/inode.c:926
#6: ffffe8ffffc22270 (&lg->lg_mutex){+.+.}-{4:4}, at: ext4_mb_group_or_file fs/ext4/mballoc.c:5878 [inline]
#6: ffffe8ffffc22270 (&lg->lg_mutex){+.+.}-{4:4}, at: ext4_mb_initialize_context+0x854/0xc20 fs/ext4/mballoc.c:5922
locks held by khungtaskd/35: 1, last CPU#0:
#0: ffffffff9035a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff9035a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff9035a560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5396: 2, on CPU#1:
#0: ffff8880380e10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032532e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5653 Comm: sshd-session Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:__list_add_valid_or_report+0x5b/0x130 lib/list_debug.c:32
Code: ff df 4c 8d 63 08 4c 89 e5 48 c1 ed 03 42 80 7c 2d 00 00 74 08 4c 89 e7 e8 12 ad 39 fd 4d 39 34 24 75 71 4d 89 f4 49 c1 ec 03 <43> 80 3c 2c 00 74 08 4c 89 f7 e8 f6 ac 39 fd 49 39 1e 0f 85 83 00
RSP: 0018:ffffc90003baf758 EFLAGS: 00000806
RAX: ffffc90003bafa00 RBX: ffff888021b9a4c8 RCX: 0000000000000001
RDX: ffff888021b9a4c8 RSI: ffff888021b9a4c8 RDI: ffffc90003bafa18
RBP: 1ffff1100437349a R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000775ee0 R12: 1ffff11004373499
R13: dffffc0000000000 R14: ffff888021b9a4c8 R15: ffffc90003bafa18
FS: 00007f8111186300(0000) GS:ffff888123259000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 0000000073e14000 CR4: 00000000003526f0
Call Trace:
__list_add_valid include/linux/list.h:104 [inline]
__list_add include/linux/list.h:169 [inline]
list_add include/linux/list.h:192 [inline]
__add_wait_queue include/linux/wait.h:181 [inline]
add_wait_queue+0xba/0x180 kernel/sched/wait.c:25
poll_wait include/linux/poll.h:45 [inline]
pipe_poll+0x17a/0x570 fs/pipe.c:759
vfs_poll include/linux/poll.h:82 [inline]
do_pollfd fs/select.c:877 [inline]
do_poll fs/select.c:920 [inline]
do_sys_poll+0x98f/0x1150 fs/select.c:1015
__do_sys_ppoll fs/select.c:1112 [inline]
__se_sys_ppoll+0x209/0x2b0 fs/select.c:1092
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x00007f8110aa7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffef0a36210 EFLAGS: 00000202 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 00007f8111186300 RCX: 00007f8110aa7407
RDX: 00007ffef0a36250 RSI: 0000000000000004 RDI: 000055b63952a150
RBP: 00007ffef0a362c0 R08: 0000000000000008 R09: 0000000000000000
R10: 00007ffef0a36350 R11: 0000000000000202 R12: 0000000000000001
R13: 00007ffef0a36350 R14: 0000000000000123 R15: 0000000000000004