INFO: task syz.2.3772:19336 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3772 state:D stack:25160 pid:19336 tgid:19336 ppid:10622 task_flags:0x40044c flags:0x00080003
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
schedule_timeout+0x9a/0x270 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+0x2bf/0x5d0 kernel/sched/completion.c:153
__flush_work+0x9c1/0xd20 kernel/workqueue.c:4273
__cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4393
hci_cmd_sync_clear+0x30/0x230 net/bluetooth/hci_sync.c:655
hci_unregister_dev+0x194/0x510 net/bluetooth/hci_core.c:2711
vhci_release+0x155/0x1b0 drivers/bluetooth/hci_vhci.c:690
__fput+0x45b/0xa80 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
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: 0033:0x7fbc44bff749
RSP: 002b:00007ffe2ccacc28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000175313 RCX: 00007fbc44bff749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fbc44e57da0 R08: 0000000000000001 R09: 000000182ccacf1f
R10: 0000001b31b20000 R11: 0000000000000246 R12: 00007fbc44e55fac
R13: 00007fbc44e55fa0 R14: ffffffffffffffff R15: 00007ffe2ccacd40
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
3 locks held by kworker/u8:5/155:
#0: ffff888030448138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888030448138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc900039dfba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900039dfba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194
2 locks held by getty/5559:
#0: ffff88823bf360a0 (&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
3 locks held by kworker/u8:14/6171:
#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: ffffc900056c7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900056c7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by kworker/u8:16/6259:
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90003bdfba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90003bdfba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e856ac0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669
#3: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x140 net/wireless/core.c:1677
3 locks held by kworker/u9:2/16568:
#0: ffff88804a1d1138 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88804a1d1138 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90005137ba0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90005137ba0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff88803d6e4e88 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331
3 locks held by syz-executor/18063:
7 locks held by kworker/0:1H/18573:
8 locks held by kworker/u8:3/19064:
5 locks held by kworker/u8:9/19905:
3 locks held by syz-executor/20107:
2 locks held by udevd/20125:
2 locks held by syz-executor/20141:
#0: ffffffff8ed83080 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ed83080 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8ed83080 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
2 locks held by syz-executor/20302:
#0: ffffffff8ed7e7d0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ed7e7d0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8ed7e7d0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e8639b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
1 lock held by syz.6.4067/20400:
#0: ffff88802fd16a90 (&substream->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#0: ffff88802fd16a90 (&substream->lock){+.+.}-{3:3}, at: remove_wait_queue+0x23/0x110 kernel/sched/wait.c:73
8 locks held by syz.6.4067/20401:
#0: ffff88803983df58 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1679 [inline]
#0: ffff88803983df58 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_connect net/sctp/socket.c:4812 [inline]
#0: ffff88803983df58 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_inet_connect+0xa0/0x1e0 net/sctp/socket.c:4834
#1: ffff8880b883add8 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
#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: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline]
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x19c/0x4a0 kernel/trace/bpf_trace.c:2118
#3: ffff8880b8924148 (psi_seq){-...}-{0:0}, at: rt_mutex_slowunlock+0xb0/0x8a0 kernel/locking/rtmutex.c:1417
#4: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#4: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#4: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#4: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1c1/0x3e0 kernel/locking/spinlock_rt.c:57
#5: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#5: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#5: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline]
#5: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x19c/0x4a0 kernel/trace/bpf_trace.c:2118
#6: ffff8880b883add8 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
#7: ffff8880390f68b8 (&mm->cpus_allowed_lock#2){....}-{2:2}, at: mm_set_cpus_allowed include/linux/mm_types.h:1473 [inline]
#7: ffff8880390f68b8 (&mm->cpus_allowed_lock#2){....}-{2:2}, at: __do_set_cpus_allowed+0x367/0x7a0 kernel/sched/core.c:2733
1 lock held by syz.6.4067/20402:
#0: ffff88803983df58 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1679 [inline]
#0: ffff88803983df58 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_setsockopt+0x1f7/0x1200 net/sctp/socket.c:4600
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18573 Comm: kworker/0:1H Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:probe_sched_switch+0x25/0x90 kernel/trace/trace_sched_switch.c:31
Code: 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 54 53 48 89 cb 49 89 d6 e8 49 52 f8 ff 8b 35 83 6c ec 16 31 ed 85 f6 40 0f 95 c5 <31> ff e8 e4 56 f8 ff 01 ed 44 8b 3d 4b 6c ec 16 31 ff 44 89 fe e8
RSP: 0018:ffffc90005627488 EFLAGS: 00000046
RAX: ffffffff81c65af7 RBX: ffff88802541da00 RCX: ffff88802cb78000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 1ffffffff1dac84e
R10: dffffc0000000000 R11: ffffffff81c65ae0 R12: ffff88802365df90
R13: ffffffff81c65ae0 R14: ffff88802cb78000 R15: ffff88802cb78000
FS: 0000000000000000(0000) GS:ffff888126df6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000005dc6a000 CR4: 00000000003526f0
Call Trace:
__traceiter_sched_switch+0x9d/0xd0 include/trace/events/sched.h:220
__do_trace_sched_switch include/trace/events/sched.h:220 [inline]
trace_sched_switch include/trace/events/sched.h:220 [inline]
__schedule+0x22e9/0x4c20 kernel/sched/core.c:6926
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
class_preempt_destructor include/linux/preempt.h:470 [inline]
try_to_wake_up+0x82b/0x12b0 kernel/sched/core.c:4300
__wake_up_common kernel/sched/wait.c:108 [inline]
__wake_up_common_lock+0x136/0x1e0 kernel/sched/wait.c:125
__snd_rawmidi_transmit_ack+0x27b/0x330 sound/core/rawmidi.c:1448
snd_rawmidi_transmit+0x7b/0xf0 sound/core/rawmidi.c:1492
snd_vmidi_output_work+0x1a3/0x410 sound/core/seq/seq_virmidi.c:151
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