INFO: task syz-executor:5813 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:21736 pid:5813 tgid:5813 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
__writeback_inodes_sb_nr+0x1f7/0x270 fs/fs-writeback.c:2787
sync_filesystem+0xa2/0x250 fs/sync.c:54
generic_shutdown_super+0x6f/0x2c0 fs/super.c:621
kill_block_super+0x44/0x90 fs/super.c:1722
deactivate_locked_super+0xbc/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f002e8609f7
RSP: 002b:00007ffe22d675b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f002e8e1d7d RCX: 00007f002e8609f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe22d67670
RBP: 00007ffe22d67670 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe22d68700
R13: 00007f002e8e1d7d R14: 000000000007ae36 R15: 00007ffe22d68740
INFO: task kworker/u8:0:10759 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:21160 pid:10759 tgid:10759 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
io_schedule+0x81/0xe0 kernel/sched/core.c:7871
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:1564 [inline]
__writeback_single_inode+0x6f4/0x1000 fs/fs-writeback.c:1784
writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:2015
wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195
wb_do_writeback fs/fs-writeback.c:2342 [inline]
wb_workfn+0x40e/0xf00 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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:
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:2/43:
7 locks held by kworker/u8:8/3604:
2 locks held by kworker/u8:10/4847:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000f86fba0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000f86fba0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
1 lock held by udevd/5167:
#0: ffff8880362b0a08 (&ep->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#0: ffff8880362b0a08 (&ep->lock){+.+.}-{3:3}, at: ep_poll fs/eventpoll.c:2040 [inline]
#0: ffff8880362b0a08 (&ep->lock){+.+.}-{3:3}, at: do_epoll_wait+0x848/0xbb0 fs/eventpoll.c:2473
2 locks held by getty/5553:
#0: ffff88823bf3e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5813:
#0: ffff88802f3c40d0 (&type->s_umount_key#102){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802f3c40d0 (&type->s_umount_key#102){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802f3c40d0 (&type->s_umount_key#102){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
2 locks held by kworker/u8:0/10759:
#0: ffff88814045c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88814045c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000f9bfba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000f9bfba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by kworker/u8:6/11492:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9001bf8fba0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9001bf8fba0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
7 locks held by syz-executor/12658:
4 locks held by syz-executor/13190:
#0: ffffffff98b52ed0 (&fsnotify_mark_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#0: ffffffff98b52ed0 (&fsnotify_mark_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#0: ffffffff98b52ed0 (&fsnotify_mark_srcu){.+.+}-{0:0}, at: fsnotify+0x735/0x1aa0 fs/notify/fsnotify.c:612
#1: ffff8880301ef0f8 (&group->notification_waitq){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#1: ffff8880301ef0f8 (&group->notification_waitq){+.+.}-{3:3}, at: __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1c1/0x3e0 kernel/locking/spinlock_rt.c:57
#3: ffff8880362b0a08 (&ep->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#3: ffff8880362b0a08 (&ep->lock){+.+.}-{3:3}, at: ep_poll_callback+0x79/0x800 fs/eventpoll.c:1256
2 locks held by udevd/13212:
1 lock held by udevd/13213:
7 locks held by udevd/13628:
2 locks held by udevd/13834:
1 lock held by syz.0.2773/15165:
4 locks held by syz.8.2774/15172:
5 locks held by syz.7.2778/15185:
=============================================
NMI backtrace for cpu 0
CPU: 0 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+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 43 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: 0x0 (bat_events)
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x31/0xa0 kernel/kcov.c:314
Code: 24 65 48 8b 0c 25 08 90 a2 91 65 44 8b 05 c7 dd e3 0f 41 81 e0 00 00 ff 00 ba 00 01 00 00 23 91 4c 0b 00 00 41 89 d1 45 09 c1 <74> 12 45 85 c0 75 5f 85 d2 74 5b 83 b9 14 16 00 00 00 74 52 8b 91
RSP: 0018:ffffc90000b476b8 EFLAGS: 00000046
RAX: ffffffff81ac170d RBX: 0000000000000008 RCX: ffff8881416a1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8880b8927f00 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000168eb4 R12: dffffc0000000000
R13: ffff8880b893b808 R14: ffff8880b893b801 R15: 00000097d47e429f
FS: 0000000000000000(0000) GS:ffff888126ef7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558873a808 CR3: 0000000032eca000 CR4: 00000000003526f0
Call Trace:
__hrtimer_start_range_ns kernel/time/hrtimer.c:1248 [inline]
hrtimer_start_range_ns+0x30d/0x10a0 kernel/time/hrtimer.c:1322
hrtimer_start include/linux/hrtimer.h:259 [inline]
start_dl_timer+0x359/0x4f0 kernel/sched/deadline.c:1129
update_curr_dl_se+0x3c2/0x990 kernel/sched/deadline.c:1470
update_curr+0x3fb/0x730 kernel/sched/fair.c:1243
dequeue_entity kernel/sched/fair.c:5375 [inline]
dequeue_entities+0x1b3/0x2f70 kernel/sched/fair.c:7073
dequeue_task_fair+0x20e/0x790 kernel/sched/fair.c:7172
block_task kernel/sched/core.c:2157 [inline]
try_to_block_task kernel/sched/core.c:6553 [inline]
__schedule+0x5a2/0x4c20 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
worker_thread+0xa82/0xda0 kernel/workqueue.c:3442
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245