INFO: task kworker/u8:12:3325 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:21920 pid:3325 tgid:3325 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: pm_fs_sync pm_fs_sync_work_fn
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
sync_bdevs+0x276/0x470 block/bdev.c:1369
ksys_sync+0xc5/0x120 fs/sync.c:105
ksys_sync_helper+0x17/0xa0 kernel/power/main.c:90
pm_fs_sync_work_fn+0xf/0x70 kernel/power/main.c:112
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
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 khungtaskd/33: 1, last CPU#1:
#0: ffffffff8fd5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fd5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fd5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:12/3325: 3, on CPU#0:
#0: ffff888020ae2940 ((wq_completion)pm_fs_sync){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888020ae2940 ((wq_completion)pm_fs_sync){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888020ae2940 ((wq_completion)pm_fs_sync){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888020ae2940 ((wq_completion)pm_fs_sync){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000e49fc40 (pm_fs_sync_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000e49fc40 (pm_fs_sync_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000e49fc40 (pm_fs_sync_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000e49fc40 (pm_fs_sync_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff888027414350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x276/0x470 block/bdev.c:1369
locks held by getty/5371: 2, on CPU#1:
#0: ffff888037b480a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000323b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u9:4/5627: 3, on CPU#0:
#0: ffff88807cf6b940 ((wq_completion)hci6){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88807cf6b940 ((wq_completion)hci6){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88807cf6b940 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88807cf6b940 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90003517c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90003517c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90003517c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90003517c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff88807a9e8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x242/0x430 net/bluetooth/hci_sync.c:337
locks held by udevd/5632: 1, on CPU#1:
#0: ffff888027414350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz.0.449/7094: 5, on CPU#0:
#0: ffff888076c555f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff88802c850460 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2756 [inline]
#1: ffff88802c850460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffff8880531db480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
#3: ffff8880206dc5a8 (kn->active#75){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#3: ffff8880206dc5a8 (kn->active#75){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
#4: ffffffff8fc04720 (system_transition_mutex){+.+.}-{4:4}, at: enter_state kernel/power/suspend.c:591 [inline]
#4: ffffffff8fc04720 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x127/0x760 kernel/power/suspend.c:644
locks held by syz-executor/8393: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz.4.1049/8872: 2, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
#1: ffffffff8fc04720 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x49/0x70 kernel/power/main.c:71
locks held by syz.7.1061/8908: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz.1.1069/8977: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz.1.1069/8979: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz.5.1076/9001: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz.2.1094/9064: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9066: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9068: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9070: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9072: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9074: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9080: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9082: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9084: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9086: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9088: 1, on CPU#1:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
locks held by syz-executor/9090: 1, on CPU#0:
#0: ffffffff906a0400 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 33 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
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: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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 1b 8b 02 e9 6e 8f 27 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 d5 20 00 fb f4 47 8f 27 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8fa07ca0 EFLAGS: 00000242
RAX: 000000000013d8bf RBX: ffffffff819becb0 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e469729 RDI: ffffffff8c6dde80
RBP: ffffffff8fa07d78 R08: ffff8880b8433a1b R09: 1ffff11017086743
R10: dffffc0000000000 R11: ffffed1017086744 R12: 0000000000000000
R13: 1ffffffff1f51e00 R14: 1ffffffff1f40f9c R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888123abf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f22240d6057 CR3: 000000007c642000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:767 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:768
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
rest_init+0x378/0x3a0 init/main.c:732
start_kernel+0x392/0x3e0 init/main.c:1190
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x157