INFO: task syz.3.292:6926 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.292 state:D stack:28552 pid:6926 tgid:6924 ppid:5628 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d4/0x5630 kernel/sched/core.c:7239
__schedule_loop kernel/sched/core.c:7316 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7331
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7388
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
device_lock include/linux/device.h:1104 [inline]
usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
chrdev_open+0x4d9/0x600 fs/char_dev.c:411
do_dentry_open+0x816/0x1380 fs/open.c:996
vfs_open+0x3b/0x340 fs/open.c:1101
do_open fs/namei.c:4837 [inline]
path_openat+0x1443/0x1d60 fs/namei.c:5000
do_file_open+0x23e/0x4a0 fs/namei.c:5029
do_sys_openat2+0x115/0x200 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1434
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: 0033:0x7faf11f5e90e
RSP: 002b:00007faf12eadb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007faf12eae6c0 RCX: 00007faf11f5e90e
RDX: 0000000000002081 RSI: 00007faf12eadc00 RDI: ffffffffffffff9c
RBP: 00007faf12eadc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007faf12226038 R14: 00007faf12225fa0 R15: 00007faf1234fa48
Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#1:
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6793
locks held by getty/5374: 2, on CPU#0:
#0: ffff888035cdc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/0:4/5683: 6, on CPU#0:
#0: ffff8880226c6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff8880226c6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
#1: ffffc90004a67c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90004a67c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
#2: ffff888028c7b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff888028c7b1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907
#3: ffff888028c78568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3260 [inline]
#3: ffff888028c78568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5472 [inline]
#3: ffff888028c78568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#3: ffff888028c78568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#3: ffff888028c78568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5961
#4: ffff888029bfa160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5473 [inline]
#4: ffff888029bfa160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#4: ffff888029bfa160 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#4: ffff888029bfa160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961
#5: ffffffff8f8d7d48 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14d/0x1810 drivers/usb/core/hub.c:3075
locks held by kworker/1:9/5735: 9, last CPU#1:
#0: ffff8880226c6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff8880226c6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
#1: ffffc90004defc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90004defc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
#2: ffff888028e4d1d8
(&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
(&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907
#3: ffff88807e6251d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff88807e6251d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2336
#4: ffff888030bb71a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff888030bb71a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff888030bb71a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
#5: ffffffff903d8780 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
#5: ffffffff903d8780 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast+0x27e/0x560 lib/kobject_uevent.c:410
#6: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#6: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#6: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#6: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: kernfs_root+0x1c/0x230 fs/kernfs/kernfs-internal.h:76
#7: ffff88807f2650a0 (&ep->wq){....}-{3:3}, at: __wake_up_common_lock+0x30/0x1f0 kernel/sched/wait.c:124
#8: ffff8880b873b2e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
locks held by syz.3.292/6926: 1, on CPU#1:
#0: ffff888028e4d1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#0: ffff888028e4d1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.2.331/7099: 1, last CPU#1:
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.1.939/9397: 1, on CPU#0:
#0: ffff888028c7b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#0: ffff888028c7b1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.1.939/9400: 3, on CPU#0:
#0: ffffffff9001b8e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575
#1: ffffffff9002a480 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff9002a480 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0 net/core/net_namespace.c:248
#2: ffffffff8eb603e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8eb603e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
locks held by syz.4.940/9399: 1, on CPU#1:
#0: ffffffff8eb602b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
=============================================
NMI backtrace for cpu 0
CPU: 0 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 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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/0x480 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7099 Comm: syz.2.331 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:check_preemption_disabled+0x1/0xd0 lib/smp_processor_id.c:13
Code: 20 dd 4b 8c 48 c7 c6 60 dd 4b 8c eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 53 65 8b 05 4b 4e 99 07 65 48 8b 0d 1b 4e 99 07 85 c9
RSP: 0018:ffffc90003767470 EFLAGS: 00000092
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000005a44979c RSI: ffffffff8e4b5735 RDI: ffffffff8c4bdd80
RBP: ffffffff8177710f R08: ffffffff8177710f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb5a0e0 R12: 0000000000000002
R13: ffffffff8eb5a0e0 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff88812503f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000ce0 CR3: 000000007818c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000ffff000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_acquire+0x116/0x350 kernel/locking/lockdep.c:5888
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_pages_prepare+0x960/0xa60 mm/page_alloc.c:1451
__free_contig_range_common+0x174/0x340 mm/page_alloc.c:6897
__free_contig_range mm/page_alloc.c:6942 [inline]
free_pages_bulk+0x48/0x120 mm/page_alloc.c:5257
vm_area_free_pages mm/vmalloc.c:3461 [inline]
vfree+0x226/0x4a0 mm/vmalloc.c:3510
kcov_put kernel/kcov.c:449 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:554
__fput+0x418/0xa50 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1009
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
get_signal+0x121b/0x12c0 kernel/signal.c:3046
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3ca135e90e
Code: Unable to access opcode bytes at 0x7f3ca135e8e4.
RSP: 002b:00007f3ca2242f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f3ca22436c0 RCX: 00007f3ca135e90e
RDX: 00007f3ca2242fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3ca1435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ca1626038 R14: 00007f3ca1625fa0 R15: 00007f3ca174fa48