INFO: task syz.3.1683:21356 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1683 state:D stack:25096 pid:21356 tgid:21354 ppid:5595 task_flags:0x400140 flags:0x00080003
Call Trace:
__schedu
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x16d9/0x5700 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
kthread_flush_worker+0x138/0x1a0 kernel/kthread.c:1579
__alloc_workqueue+0x16f4/0x1fe0 kernel/workqueue.c:6011
alloc_workqueue_va kernel/workqueue.c:6033 [inline]
alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:6049
btrfs_alloc_ordered_workqueue+0x1c3/0x290 fs/btrfs/async-thread.c:140
btrfs_init_workqueues+0x398/0x680 fs/btrfs/disk-io.c:1990
open_ctree+0x14d0/0x4190 fs/btrfs/disk-io.c:3540
btrfs_fill_super fs/btrfs/super.c:974 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1969 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2112 [inline]
btrfs_get_tree+0x1084/0x1980 fs/btrfs/super.c:2146
vfs_get_tree+0x92/0x2a0 fs/super.c:1932
fc_mount fs/namespace.c:1198 [inline]
do_new_mount_fc fs/namespace.c:3772 [inline]
do_new_mount+0x319/0xdc0 fs/namespace.c:3848
do_mount fs/namespace.c:4181 [inline]
__do_sys_mount fs/namespace.c:4397 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4374
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5846aff40a
RSP: 002b:00007f5844d55e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5844d55ee0 RCX: 00007f5846aff40a
RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007f5844d55ea0
RBP: 0000200000005100 R08: 00007f5844d55ee0 R09: 0000000000800810
R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f5844d55ea0 R14: 000000000000510a R15: 0000200000000140
Showing all locks held in the system:
locks held by rcuc/0/20: 3, last CPU#0:
#0: ffffffff8e059540 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3d/0x420 kernel/softirq.c:186
#1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3d/0x420 kernel/softirq.c:186
#2: ffffffff8e1c3de0 (rcu_callback){....}-{0:0}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#2: ffffffff8e1c3de0 (rcu_callback){....}-{0:0}, at: rcu_cpu_kthread+0x217/0x1740 kernel/rcu/tree.c:3000
locks held by khungtaskd/39: 1, last CPU#1:
#0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:9/1173: 6, on CPU#1:
#0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000628fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000628fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000628fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000628fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff8f5c7140 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
#3: ffff8880b8743418 (&pcp->lock){+.+.}-{3:3}, at: free_frozen_page_commit+0x815/0x1850 mm/page_alloc.c:2908
#4: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#4: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#4: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_trylock kernel/locking/spinlock_rt.c:127 [inline]
#4: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x10c/0x2b0 kernel/locking/spinlock_rt.c:135
#5: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#5: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:643 [inline]
#5: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: free_pcppages_bulk+0x61/0x540 mm/page_alloc.c:1487
locks held by kworker/u8:17/2263: 3, on CPU#1:
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90008227c40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90008227c40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90008227c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90008227c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
locks held by getty/5350: 2, on CPU#1:
#0: ffff8880357a20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900044db2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5593: 2, last CPU#0:
#0: ffff88802a3460e0 (&type->s_umount_key#60){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88802a3460e0 (&type->s_umount_key#60){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88802a3460e0 (&type->s_umount_key#60){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffff88806039f138 ((wq_completion)xfs-blockgc/loop1#68){+.+.}-{0:0}, at: touch_wq_lockdep_map+0xb5/0x180 kernel/workqueue.c:4111
locks held by kworker/u8:3/14396: 2, on CPU#1:
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9001f6cfc40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9001f6cfc40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9001f6cfc40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9001f6cfc40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz.3.1683/21356: 1, on CPU#0:
#0: ffff88802c0480e0 (&type->s_umount_key#59/1){+.+.}-{4:4}, at: alloc_super fs/super.c:351 [inline]
#0: ffff88802c0480e0 (&type->s_umount_key#59/1){+.+.}-{4:4}, at: sget_fc+0x9d4/0x1a80 fs/super.c:874
locks held by syz-executor/21969: 7, on CPU#1:
#0: ffff8880362dc510 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff8880362dc510 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#1: ffff88804ccb2078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336
#2: ffff8880287405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff8880287405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337
#3: ffffffff8ee45df8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x6d0 drivers/net/netdevsim/bus.c:184
#4: ffff8880621ad160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff8880621ad160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#5: ffff88803a728310 (&devlink->lock_key#6){+.+.}-{4:4}, at: nsim_drv_probe+0xfb/0xbc0 drivers/net/netdevsim/dev.c:1583
#6: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#6: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2188
locks held by syz-executor/22001: 4, on CPU#0:
#0: ffff8880362dc510 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff8880362dc510 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#1: ffff888035fa1c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336
#2: ffff8880287405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff8880287405a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337
#3: ffffffff8ee45df8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x6d0 drivers/net/netdevsim/bus.c:184
locks held by syz-executor/22056: 1, on CPU#0:
#0: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
#0: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3587
locks held by syz-executor/22473: 2, on CPU#1:
#0: ffffffff8fb3e388 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fb3e388 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fb3e388 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595
#1: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#1: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by syz-executor/22496: 2, on CPU#0:
#0: ffffffff8f5c7140 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780 net/core/net_namespace.c:578
#1: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:149 [inline]
#1: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11660
locks held by syz-executor/22560: 1, on CPU#0:
#0: ffffffff8f5d5978 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3dd/0x1e70 drivers/net/tun.c:3229
locks held by dhcpcd-run-hook/22649: 2, last CPU#0:
#0: ffff8880352f2bc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#1: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: rmqueue_buddy mm/page_alloc.c:3234 [inline]
#1: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: rmqueue mm/page_alloc.c:3427 [inline]
#1: ffff88813fffc2d8 (&zone->lock){+.+.}-{3:3}, at: get_page_from_freelist+0xc5f/0x2600 mm/page_alloc.c:3940
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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/0x470 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: 22649 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0033:0x7fdb1447f398
Code: 00 00 c7 44 24 04 30 00 00 00 e8 ae fe ff ff e8 9a ef ff ff 6a 01 5f e8 65 e9 ff ff 48 8d 05 cf d0 07 00 41 56 41 55 4c 8b 30 <41> 54 49 89 fc 55 53 41 8a 5e 54 83 e3 01 09 f3 e8 60 e9 ff ff 48
RSP: 002b:00007ffd072c5258 EFLAGS: 00000206
RAX: 00007fdb144fc460 RBX: 0000560d77eb26a0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000560d77eb9400
RBP: 0000000000000000 R08: 00007fdb1442cac0 R09: 0000000000000020
R10: 0000000000000000 R11: 0000000000000001 R12: 0000560d77ec0ff8
R13: 0000000000000001 R14: 0000560d77eb0910 R15: 0000000000000000
FS: 00007fdb14192c80 GS: 0000000000000000