INFO: task syz.7.1279:12085 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1279 state:D stack:23544 pid:12085 tgid:12084 ppid:8128 task_flags:0x480140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
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
i2c_del_adapter+0x581/0x6e0 drivers/i2c/i2c-core-base.c:1817
dvb_usb_i2c_exit+0x64/0xb0 drivers/media/usb/dvb-usb/dvb-usb-i2c.c:46
dvb_usb_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:144 [inline]
dvb_usb_device_exit+0x1be/0x350 drivers/media/usb/dvb-usb/dvb-usb-init.c:338
usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:571 [inline]
__device_release_driver drivers/base/dd.c:1274 [inline]
device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1297
bus_remove_device+0x34d/0x410 drivers/base/bus.c:579
device_del+0x511/0x8e0 drivers/base/core.c:3878
usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418
usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2344
hub_quiesce+0x171/0x330 drivers/usb/core/hub.c:1409
hub_disconnect+0xc8/0x470 drivers/usb/core/hub.c:1815
usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:571 [inline]
__device_release_driver drivers/base/dd.c:1274 [inline]
device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1297
proc_disconnect_claim+0x2e1/0x350 drivers/usb/core/devio.c:2492
usbdev_do_ioctl drivers/usb/core/devio.c:2783 [inline]
usbdev_ioctl+0x131b/0x20c0 drivers/usb/core/devio.c:2827
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa3fab8eba9
RSP: 002b:00007fa3fbb00038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa3fadd5fa0 RCX: 00007fa3fab8eba9
RDX: 0000200000000380 RSI: 000000008108551b RDI: 0000000000000009
RBP: 00007fa3fac11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3fadd6038 R14: 00007fa3fadd5fa0 R15: 00007fff21c36b68
INFO: task syz.7.1279:12089 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1279 state:D stack:28264 pid:12089 tgid:12084 ppid:8128 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
device_lock include/linux/device.h:914 [inline]
usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa3fab8eba9
RSP: 002b:00007fa3fb94e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa3fadd6090 RCX: 00007fa3fab8eba9
RDX: 00002000000001c0 RSI: 000000008004550f RDI: 0000000000000009
RBP: 00007fa3fac11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3fadd6128 R14: 00007fa3fadd6090 R15: 00007fff21c36b68
Showing all locks held in the system:
2 locks held by kworker/0:1/10:
3 locks held by kworker/0:0H/11:
1 lock held by khungtaskd/31:
#0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by udevd/5233:
2 locks held by getty/5621:
#0: ffff8880300b20a0 (&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
4 locks held by kworker/0:4/5971:
3 locks held by kworker/0:5/5972:
#0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004f9fba0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004f9fba0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
4 locks held by kworker/u8:12/7035:
4 locks held by syz.7.1279/12085:
#0: ffff8881457b9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff8881457b9198 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
#0: ffff8881457b9198 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
#1: ffff8881457ba160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#1: ffff8881457ba160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#1: ffff8881457ba160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#2: ffff88806cbcb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff88806cbcb198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2335
#3: ffff88806d572160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88806d572160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#3: ffff88806d572160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
1 lock held by syz.7.1279/12089:
#0: ffff8881457b9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff8881457b9198 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
#0: ffff8881457b9198 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
2 locks held by kworker/u8:31/12586:
#0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90003b1fba0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90003b1fba0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
3 locks held by kworker/u8:36/12592:
#0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90003abfba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90003abfba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by udevd/13378:
2 locks held by syz-executor/14072:
#0: ffffffff8f733bb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566
#1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
#1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11368
1 lock held by syz.0.1723/14082:
#0: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: arp_ioctl+0x2f5/0x450 net/ipv4/arp.c:1305
2 locks held by syz.0.1723/14083:
2 locks held by syz.1.1725/14092:
#0: ffffffff8e1f87c8 (sched_core_mutex){+.+.}-{4:4}, at: sched_core_get+0x52/0x170 kernel/sched/core.c:482
#1: ffffffff8e3422b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e3422b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
2 locks held by syz.1.1725/14101:
#0: ffffffff8fc592f8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8fc592f8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8fc592f8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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: 11 Comm: kworker/0:0H Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:snd_midi_event_encode_byte+0xe9/0xd00 sound/core/seq/seq_midi_event.c:184
Code: c3 e9 5e 07 00 00 49 8d 7f 20 48 89 7c 24 10 e8 2d e2 56 02 48 89 44 24 28 45 0f b6 f5 bf ff 00 00 00 44 89 f6 e8 c7 06 91 f8 <45> 84 ed 44 89 74 24 24 0f 88 e7 00 00 00 e8 b4 03 91 f8 4d 89 fc
RSP: 0018:ffffc90000107918 EFLAGS: 00000093
RAX: ffffffff892eb7a9 RBX: ffff88802ecae728 RCX: 0000000000000000
RDX: ffff88801d2cbc80 RSI: 0000000000000000 RDI: 00000000000000ff
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000020f00 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88807cf3e400
FS: 0000000000000000(0000) GS:ffff8881259e8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3c3ae7 CR3: 0000000053ffe000 CR4: 00000000003526f0
Call Trace:
snd_vmidi_output_work+0x1eb/0x410 sound/core/seq/seq_virmidi.c:153
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