INFO: task syz-executor:7712 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-syzkaller-00378-gb67ec639010f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:18984 pid:7712 tgid:7712 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
__writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2747
sync_filesystem+0xa3/0x230 fs/sync.c:54
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618
deactivate_locked_super+0xb9/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417
task_work_run+0x1d1/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc26a78fc57
RSP: 002b:00007ffc6d65a9b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc26a810925 RCX: 00007fc26a78fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc6d65aa70
RBP: 00007ffc6d65aa70 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc6d65bb00
R13: 00007fc26a810925 R14: 000000000003b5a7 R15: 00007ffc6d65bb40
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90000117bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000117bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
1 lock held by khungtaskd/31:
#0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:2/36:
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90000ac7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000ac7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
2 locks held by kworker/u8:4/59:
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000210fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000210fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
2 locks held by kworker/u8:5/1108:
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880206f8148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90003d3fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003d3fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
4 locks held by kworker/u8:8/3565:
#0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000cb37bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000cb37bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f4f0fd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
#3: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12630
1 lock held by dhcpcd/5484:
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121
2 locks held by getty/5584:
#0: ffff8880353b80a0 (&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/u8:9/7683:
1 lock held by syz-executor/7712:
#0: ffff88806a0b20e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88806a0b20e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88806a0b20e0 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
1 lock held by syz-executor/7780:
#0: ffff88802927c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802927c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802927c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
1 lock held by syz-executor/8013:
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
3 locks held by kworker/u8:12/8344:
#0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90004bf7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90004bf7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by syz-executor/8373:
#0: ffff88804ef660e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88804ef660e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88804ef660e0 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
1 lock held by syz-executor/8957:
#0: ffff888029a8e0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888029a8e0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888029a8e0e0 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
1 lock held by syz-executor/9260:
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
1 lock held by syz-executor/9915:
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054
1 lock held by syz-executor/10029:
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
2 locks held by syz.9.467/10054:
3 locks held by syz.9.467/10058:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00378-gb67ec639010f #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/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: 3565 Comm: kworker/u8:8 Not tainted 6.16.0-rc2-syzkaller-00378-gb67ec639010f #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
RIP: 0010:_find_next_bit+0xa5/0xe0 lib/find_bit.c:156
Code: d8 48 0f 43 c3 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 4e 8d 24 ef 49 83 c4 08 49 c1 e5 06 4d 89 e6 eb 11 4d 8b 3c 24 <49> 83 c6 08 49 83 c4 08 4d 85 ff 75 bf 49 83 c5 40 49 39 dd 73 17
RSP: 0018:ffffc9000cb374a0 EFLAGS: 00000046
RAX: 1ffffffff2c48240 RBX: 0000000000100000 RCX: 000000000000bab6
RDX: 000000000000bab6 RSI: 0000000000100000 RDI: ffffffff9622e850
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff81ab3048
R10: dffffc0000000000 R11: fffffbfff1f3fc1f R12: ffffffff96241200
R13: 0000000000094d80 R14: ffffffff96241200 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faf97d81178 CR3: 0000000077e08000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
find_next_bit include/linux/find.h:71 [inline]
zap_class+0x1f0/0x360 kernel/locking/lockdep.c:6258
__lockdep_free_key_range kernel/locking/lockdep.c:6410 [inline]
lockdep_unregister_key+0x1a6/0x310 kernel/locking/lockdep.c:6612
__qdisc_destroy+0x166/0x420 net/sched/sch_generic.c:1081
qdisc_put net/sched/sch_generic.c:1107 [inline]
dev_shutdown+0x34c/0x440 net/sched/sch_generic.c:1495
unregister_netdevice_many_notify+0xea7/0x2320 net/core/dev.c:12065
unregister_netdevice_many net/core/dev.c:12140 [inline]
default_device_exit_batch+0x819/0x890 net/core/dev.c:12644
ops_exit_list net/core/net_namespace.c:206 [inline]
ops_undo_list+0x522/0x990 net/core/net_namespace.c:253
cleanup_net+0x4c5/0x800 net/core/net_namespace.c:686
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245