INFO: task kworker/u8:12:1506 blocked 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:21304 pid:1506 tgid:1506 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x26e/0xb10 fs/jfs/jfs_txnmgr.c:375
jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x7e4/0x1240 fs/fs-writeback.c:1802
writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
wb_writeback+0x42b/0xaa0 fs/fs-writeback.c:2216
wb_do_writeback fs/fs-writeback.c:2363 [inline]
wb_workfn+0x3fe/0xee0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: task syz-executor:5798 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21592 pid:5798 tgid:5798 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
wb_wait_for_completion+0x360/0x680 fs/fs-writeback.c:226
__writeback_inodes_sb_nr+0x233/0x2b0 fs/fs-writeback.c:2808
sync_filesystem+0xa2/0x250 fs/sync.c:54
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
kill_block_super+0x44/0x90 fs/super.c:1722
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f032f1b0a77
RSP: 002b:00007ffe2266f818 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f032f233d7d RCX: 00007f032f1b0a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe2266f8d0
RBP: 00007ffe2266f8d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe22670960
R13: 00007f032f233d7d R14: 0000000000030e68 R15: 00007ffe226709a0
Showing all locks held in the system:
3 locks held by kworker/0:1/10:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:2/43:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90000b57bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000b57bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
2 locks held by kworker/u8:12/1506:
#0: ffff8881412d1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff8881412d1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000582fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000582fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
3 locks held by kworker/u8:17/3545:
#0: ffff8881412d1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff8881412d1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000d66fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000d66fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888024504408 (&wb->work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#2: ffff888024504408 (&wb->work_lock){+.+.}-{3:3}, at: get_next_work_item fs/fs-writeback.c:2266 [inline]
#2: ffff888024504408 (&wb->work_lock){+.+.}-{3:3}, at: wb_do_writeback fs/fs-writeback.c:2361 [inline]
#2: ffff888024504408 (&wb->work_lock){+.+.}-{3:3}, at: wb_workfn+0x23c/0xee0 fs/fs-writeback.c:2403
2 locks held by getty/5561:
#0: ffff88803580d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5798:
#0: ffff88805d6cc0d0 (&type->s_umount_key#68){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805d6cc0d0 (&type->s_umount_key#68){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805d6cc0d0 (&type->s_umount_key#68){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
2 locks held by kworker/u8:18/6154:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000656fbc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000656fbc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
4 locks held by syz-executor/7199:
1 lock held by udevd/7491:
1 lock held by udevd/7695:
2 locks held by syz-executor/8344:
#0: ffff88803ae7e0d0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803ae7e0d0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803ae7e0d0 (&type->s_umount_key#61){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888057043088 (&ailp->ail_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#1: ffff888057043088 (&ailp->ail_lock){+.+.}-{3:3}, at: xfs_ail_push_all_sync+0x1d5/0x2a0 fs/xfs/xfs_trans_ail.c:722
1 lock held by xfsaild/loop2/9695:
#0: ffff888057043088 (&ailp->ail_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#0: ffff888057043088 (&ailp->ail_lock){+.+.}-{3:3}, at: xfsaild_push fs/xfs/xfs_trans_ail.c:492 [inline]
#0: ffff888057043088 (&ailp->ail_lock){+.+.}-{3:3}, at: xfsaild+0x68d/0x28c0 fs/xfs/xfs_trans_ail.c:700
1 lock held by syz.5.590/9727:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 9e f3 b5 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ef 29 18 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 1a 99 cb 05 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000167950 EFLAGS: 00000202
RAX: 1ffffffff31f3500 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff98f9aff0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8509b600 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff98f9ad60 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faf36611000 CR3: 000000002863e000 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+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3109 [inline]
console_flush_one_record+0x685/0xb80 kernel/printk/printk.c:3215
legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246