INFO: task kworker/u8:7:3016 blocked for more than 143 seconds.
Not tainted 6.16.0-next-20250808-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7 state:D stack:19416 pid:3016 tgid:3016 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760
hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28
hfsplus_cat_write_inode+0x1e6/0x7a0 fs/hfsplus/inode.c:592
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
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/31:
#0:
ffffffff8e139ee0
(
rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:7/3016:
#0:
ffff88801e2fd948
(
(wq_completion)writeback
){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1:
ffffc9000b147bc0
(
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3212 [inline]
, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2:
ffff88803344e0e0 (&type->s_umount_key#91){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3:
ffff88807b6da0b0
(
&tree->tree_lock
#2
){+.+.}-{4:4}
, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28
2 locks held by getty/5623:
#0:
ffff88814da790a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/u8:11/6292:
#0: ffff88801ffc2148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801ffc2148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000b687bc0 ((work_completion)(&ctx->exit_work)
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3212 [inline]
, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
9 locks held by syz.2.190/7089:
2 locks held by syz.6.384/8398:
#0:
ffff88803344e0e0
(&type->s_umount_key
#91
){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff888142f4e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff888142f4e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.6.384/8400:
#0:
ffff88803344e0e0
(
&type->s_umount_key
#91
){++++}-{4:4}
, at: __super_lock fs/super.c:59 [inline]
, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff888142f4e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff888142f4e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
1 lock held by syz.9.396/8590:
#0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
4 locks held by cmp/8629:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0x3f9/0x770 arch/x86/kernel/process.c:148
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: 12 Comm: kworker/u8:0 Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:rcu_is_watching+0x70/0xb0 kernel/rcu/tree.c:753
Code: c3 98 df a1 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d f9 50 fa 10 74 11 83 e0 04 c1 e8 02 5b <41> 5e 41 5f e9 57 6d d7 09 cc e8 e1 67 8d ff eb e8 48 c7 c7 c0 fb
RSP: 0018:ffffc90000117968 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 99f90d1ee5d83500
RDX: 0000000000000000 RSI: ffffffff8be346e0 RDI: ffffffff8be346a0
RBP: ffffffff8b487122 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8b487050 R12: 0000000000000002
R13: ffffffff8e139ee0 R14: ffffffff8dbe2d18 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcae8204e9c CR3: 0000000076df0000 CR4: 00000000003526f0
Call Trace:
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245