INFO: task syz.5.3596:22839 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.3596 state:D stack:28728 pid:22839 tgid:22835 ppid:13614 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7376
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821
fdget_pos+0x2aa/0x380 fs/file.c:1259
class_fd_pos_constructor include/linux/file.h:85 [inline]
ksys_write+0x71/0x250 fs/read_write.c:730
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7cc719e159
RSP: 002b:00007f7cc8021028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7cc7426090 RCX: 00007f7cc719e159
RDX: 0000000000000090 RSI: 0000200000002a80 RDI: 0000000000000003
RBP: 00007f7cc723506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7cc7426128 R14: 00007f7cc7426090 R15: 00007ffdde1f19d8
Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#1:
#0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by getty/5357: 2, on CPU#0:
#0: ffff8880370330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by kworker/0:2H/5809: 3, last CPU#0:
#0: ffff88801c05ad40 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc900049a7d08 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff8880333e3950 (&substream->lock){....}-{3:3}, at: raw_spin_rq_lock_nested kernel/sched/core.c:685 [inline]
#2: ffff8880333e3950 (&substream->lock){....}-{3:3}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:669
locks held by kworker/u8:12/5873: 4, last CPU#1:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90004b9fd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802bc4b258 (&devlink->lock_key#10){+.+.}-{4:4}, at: batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1010 [inline]
#2: ffff88802bc4b258 (&devlink->lock_key#10){+.+.}-{4:4}, at: batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1005 [inline]
#2: ffff88802bc4b258 (&devlink->lock_key#10){+.+.}-{4:4}, at: batadv_iv_send_outstanding_bat_ogm_packet+0x50f/0x7d0 net/batman-adv/bat_iv_ogm.c:1924
#3: ffff8880b843bf60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:685 [inline]
#3: ffff8880b843bf60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:669
locks held by kworker/0:8/11271: 2, last CPU#0:
#0: ffff88801c059d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000467fd08 ((gc_work).work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
locks held by syz-executor/14680: 1, last CPU#1:
#0: ffff88801f724460 (sb_writers#6){.+.+}-{0:0}, at: filename_unlinkat+0x1ad/0x730 fs/namei.c:5696
locks held by syz-executor/15900: 1, last CPU#1:
#0: ffff88807be92460 (sb_writers#6){.+.+}-{0:0}, at: filename_unlinkat+0x1ad/0x730 fs/namei.c:5696
locks held by kworker/u8:34/17458: 3, last CPU#1:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000434fd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff8880778d9258 (&devlink->lock_key#14){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834
locks held by kworker/0:3/22277: 9, last CPU#0:
#0: ffff888021a91d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc900040afd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802b03f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802b03f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4420 drivers/usb/core/hub.c:5912
#3: ffff88807f5671d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff88807f5671d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2341
#4: ffff88807bf301a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff88807bf301a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff88807bf301a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369
#5: ffffffff90bce320 (register_mutex#6){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#5: ffffffff90bce320 (register_mutex#6){+.+.}-{4:4}, at: __usb_audio_disconnect sound/usb/card.c:1130 [inline]
#5: ffffffff90bce320 (register_mutex#6){+.+.}-{4:4}, at: usb_audio_disconnect+0x7b/0x310 sound/usb/card.c:1164
#6: ffff88803d06f1b0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#6: ffff88803d06f1b0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#6: ffff88803d06f1b0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369
#7: ffffffff90bc09c0 (register_mutex#8){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#7: ffffffff90bc09c0 (register_mutex#8){+.+.}-{4:4}, at: snd_seq_midisynth_remove+0x73/0x4b0 sound/core/seq/seq_midi.c:473
#8: ffffffff8edf84a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
locks held by syz.5.3596/22836: 5, last CPU#1:
#0: ffff88802cb05b30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88808c258088 (&iter->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#1: ffff88808c258088 (&iter->mutex){+.+.}-{4:4}, at: tracing_read_pipe+0x6c/0xd60 kernel/trace/trace.c:5405
#2: ffffffff8ee8b928 (trace_event_sem){++++}-{4:4}, at: tracing_read_pipe+0x4b2/0xd60 kernel/trace/trace.c:5440
#3: ffffffff8ee826c8 (all_cpu_access_lock){++++}-{4:4}, at: trace_access_lock kernel/trace/trace.c:781 [inline]
#3: ffffffff8ee826c8 (all_cpu_access_lock){++++}-{4:4}, at: tracing_read_pipe+0x4fa/0xd60 kernel/trace/trace.c:5441
#4: ffff8880b8431760 (&per_cpu(cpu_access_lock, cpu)){+.+.}-{4:4}, at: trace_access_lock kernel/trace/trace.c:784 [inline]
#4: ffff8880b8431760 (&per_cpu(cpu_access_lock, cpu)){+.+.}-{4:4}, at: tracing_read_pipe+0x532/0xd60 kernel/trace/trace.c:5441
locks held by syz.5.3596/22839: 1, on CPU#1:
#0: ffff88802cb05b30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
locks held by syz-executor/23000: 1, last CPU#1:
#0: ffff888056048460 (sb_writers#6){.+.+}-{0:0}, at: filename_unlinkat+0x1ad/0x730 fs/namei.c:5696
locks held by syz.1.3912/24345: 2, last CPU#1:
#0: ffff88803e744460 (sb_writers#6){.+.+}-{0:0}, at: get_signal+0x1f2a/0x21e0 kernel/signal.c:3097
#1: ffff88807b067b28 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88807b067b28 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x86/0x140 mm/shmem.c:3433
locks held by syz.1.3929/24372: 4, on CPU#1:
#0: ffffffff90bbcc40 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffffffff90bbcc40 (register_mutex#4){+.+.}-{4:4}, at: odev_release+0x44/0x70 sound/core/seq/oss/seq_oss.c:140
#1: ffff88803da83cb0 (&mdev->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#1: ffff88803da83cb0 (&mdev->open_mutex){+.+.}-{4:4}, at: snd_seq_oss_midi_close+0xb6/0x4b0 sound/core/seq/oss/seq_oss_midi.c:373
#2: ffff88807cf63ce0 (&grp->list_mutex){++++}-{4:4}, at: class_rwsem_write_constructor include/linux/rwsem.h:270 [inline]
#2: ffff88807cf63ce0 (&grp->list_mutex){++++}-{4:4}, at: delete_and_unsubscribe_port sound/core/seq/seq_ports.c:562 [inline]
#2: ffff88807cf63ce0 (&grp->list_mutex){++++}-{4:4}, at: snd_seq_port_disconnect+0x4e5/0x610 sound/core/seq/seq_ports.c:640
#3: ffffffff8edf84a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 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: 24373 Comm: syz.1.3929 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:437
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 cb 82 a0 f5 cc
RSP: 0018:ffffc90006caf898 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8c623900 RDI: ffffffff8e65a920
RBP: ffffffff9bba39b0 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff91455a5f R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS: 00007febc4fc46c0(0000) GS:ffff888123b4f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000c000 CR3: 000000002abfe000 CR4: 00000000003526f0
Call Trace:
trace_lock_acquire include/trace/events/lock.h:23 [inline]
lock_acquire+0x31e/0x380 kernel/locking/lockdep.c:5905
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:155 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:181
debug_object_free+0x13c/0x550 lib/debugobjects.c:1025
schedule_timeout+0x137/0x280 kernel/time/sleep_timeout.c:103
snd_rawmidi_write+0x492/0xc60 sound/core/rawmidi.c:1619
do_loop_readv_writev fs/read_write.c:851 [inline]
do_loop_readv_writev fs/read_write.c:836 [inline]
vfs_writev+0x5ed/0xdd0 fs/read_write.c:1060
do_writev+0x28a/0x340 fs/read_write.c:1104
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7febc419e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007febc4fc4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007febc4425fa0 RCX: 00007febc419e159
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000004
RBP: 00007febc423506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007febc4426038 R14: 00007febc4425fa0 R15: 00007fffbfa41878