INFO: task syz.1.958:10109 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.958 state:D stack:28808 pid:10109 tgid:10107 ppid:7836 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:682
blk_trace_ioctl+0x19b/0x430 kernel/trace/blktrace.c:724
blkdev_common_ioctl+0xdf4/0x2550 block/ioctl.c:630
blkdev_ioctl+0x4f6/0x6d0 block/ioctl.c:699
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b4fd8eec9
RSP: 002b:00007f3b4dff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3b4ffe6090 RCX: 00007f3b4fd8eec9
RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000003
RBP: 00007f3b4fe11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b4ffe6128 R14: 00007f3b4ffe6090 R15: 00007f3b5010fa28
INFO: task syz.1.958:10110 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.958 state:D stack:24744 pid:10110 tgid:10107 ppid:7836 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
blk_trace_remove kernel/trace/blktrace.c:406 [inline]
blk_trace_ioctl+0x1b9/0x430 kernel/trace/blktrace.c:727
blkdev_common_ioctl+0xdf4/0x2550 block/ioctl.c:630
blkdev_ioctl+0x4f6/0x6d0 block/ioctl.c:699
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b4fd8eec9
RSP: 002b:00007f3b4dfd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3b4ffe6180 RCX: 00007f3b4fd8eec9
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003
RBP: 00007f3b4fe11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b4ffe6218 R14: 00007f3b4ffe6180 R15: 00007f3b5010fa28
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8dd3b220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8dd3b220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8dd3b220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5600:
#0: ffff88802f9340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/1:3/5847:
#0: ffff888143ecd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888143ecd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc900040efbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900040efbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888145bb0198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888145bb0198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff888026a84198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff888026a84198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff88807b63a160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88807b63a160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
7 locks held by kworker/1:5/5923:
#0: ffff888143ecd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888143ecd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000454fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000454fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888027631198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888027631198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff888060289198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff888060289198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2335
#4: ffff88807b4cb160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88807b4cb160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff88807b4cb160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffffffff8eb3e868 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline]
#5: ffffffff8eb3e868 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x328/0x640 drivers/input/input.c:2221
#6: ffffffff8dd40cb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#6: ffffffff8dd40cb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
3 locks held by syz.1.958/10108:
1 lock held by syz.1.958/10109:
#0: ffff8880244c0928 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:682
1 lock held by syz.1.958/10110:
#0: ffff8880244c0928 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff8880244c0928 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x1b9/0x430 kernel/trace/blktrace.c:727
=============================================
NMI backtrace for cpu 0
CPU: 0 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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:158
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: 5923 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:__sanitizer_cov_trace_pc+0x46/0x70 kernel/kcov.c:222
Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c 8b 91 58 16 00 00 83 fa 02 75 21 48 8b 91 60 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 5c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2
RSP: 0018:ffffc9000454ed78 EFLAGS: 00000246
RAX: ffffffff81740bbb RBX: ffff88803012eb00 RCX: ffff88802d3c8000
RDX: ffffc900193f6000 RSI: 00000000000232dc RDI: ffff88803012eb00
RBP: ffffc9000454ef70 R08: ffffffff8f5bee37 R09: 1ffffffff1eb7dc6
R10: dffffc0000000000 R11: fffffbfff1eb7dc7 R12: 1ffff920008a9dc0
R13: dffffc0000000000 R14: ffffffff85c41832 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126488000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555c1695c8 CR3: 000000000db36000 CR4: 00000000003526f0
DR0: 0000000000000006 DR1: 0000000000000000 DR2: 0000000000000080
DR3: 000000000f000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__phys_addr+0x1b/0x180 arch/x86/mm/physaddr.c:16
virt_to_folio include/linux/mm.h:1245 [inline]
kfree+0x77/0x6d0 mm/slub.c:6765
devtmpfs_submit_req drivers/base/devtmpfs.c:124 [inline]
devtmpfs_delete_node+0x162/0x1d0 drivers/base/devtmpfs.c:171
device_del+0x2cf/0x8e0 drivers/base/core.c:3857
device_unregister drivers/base/core.c:3919 [inline]
device_destroy+0xa6/0x160 drivers/base/core.c:4473
dvb_remove_device+0x129/0x280 drivers/media/dvb-core/dvbdev.c:609
dvb_unregister_device+0x18/0xa0 drivers/media/dvb-core/dvbdev.c:637
dvb_dmxdev_release+0x4d1/0x640 drivers/media/dvb-core/dmxdev.c:1471
dvb_usb_adapter_dvb_exit+0x9a/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:224
dvb_usb_adapter_exit+0x8b/0x240 drivers/media/usb/dvb-usb/dvb-usb-init.c:128
dvb_usb_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:143 [inline]
dvb_usb_device_exit+0x1b6/0x350 drivers/media/usb/dvb-usb/dvb-usb-init.c:338
usb_unbind_interface+0x26b/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+0x4d6/0x800 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_port_connect drivers/usb/core/hub.c:5406 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
port_event drivers/usb/core/hub.c:5870 [inline]
hub_event+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245