INFO: task kworker/1:2:975 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:19848 pid:975 tgid:975 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event 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_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:1814 dvb_usbv2_probe+0x4ae/0x41a0 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:993 usb_probe_interface+0x668/0xc30 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x390 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9e0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3689 usb_new_device+0xa39/0x16f0 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2958/0x4a20 drivers/usb/core/hub.c:5952 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 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000117ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000117ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f4dfb88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by khungtaskd/31: #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/1:2/975: #0: ffff8880202d9148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8880202d9148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003777ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003777ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88823be5e998 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff88823be5e998 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff8880659b3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff8880659b3198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff888053429160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff888053429160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 2 locks held by getty/5580: #0: ffff8880338d80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:5/5919: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004d87ba0 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004d87ba0 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e142c80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820 2 locks held by dhcpcd/12984: #0: ffff888052ecd288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888052ecd288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff888052ecd288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 4 locks held by udevd/16557: #0: ffff888065c8c790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 #1: ffff888051e45488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888085614e18 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888085614e18 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff8880659b3198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline] #3: ffff8880659b3198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by kworker/1:0/16719: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90014ce7ba0 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90014ce7ba0 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 2 locks held by syz.5.2602/18505: #0: ffffffff8f4dfb88 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f4dfb88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.0.2605/18510: #0: ffffffff8e192aa8 (tracepoints_mutex){+.+.}-{4:4}, at: tracepoint_probe_unregister+0x30/0x9b0 kernel/tracepoint.c:501 2 locks held by syz.0.2605/18511: 1 lock held by syz.4.2606/18515: #0: ffffffff8e192aa8 (tracepoints_mutex){+.+.}-{4:4}, at: tracepoint_probe_unregister+0x30/0x9b0 kernel/tracepoint.c:501 1 lock held by syz.6.2608/18525: #0: ffffffff8e192aa8 (tracepoints_mutex){+.+.}-{4:4}, at: tracepoint_probe_register_prio_may_exist+0x43/0xa0 kernel/tracepoint.c:431 1 lock held by syz.3.2610/18535: #0: ffffffff8f4dfb88 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3078 1 lock held by syz.3.2610/18538: #0: ffffffff8f4dfb88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f4dfb88 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:837 1 lock held by syz.3.2610/18541: #0: ffffffff8e192aa8 (tracepoints_mutex){+.+.}-{4:4}, at: tracepoint_probe_register_prio_may_exist+0x43/0xa0 kernel/tracepoint.c:431 ============================================= 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 10/02/2025 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18511 Comm: syz.0.2605 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__module_address+0x14/0x3e0 kernel/module/main.c:3815 Code: 33 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 57 41 56 41 55 41 54 53 48 3b 3d 0c e2 36 0c <0f> 82 8a 02 00 00 48 3b 3d 07 e2 36 0c 0f 87 7d 02 00 00 49 89 fd RSP: 0018:ffffc9000b0b6cf0 EFLAGS: 00000217 RAX: 0000000000000001 RBX: ffffffff81aa34ad RCX: 54e9057246097000 RDX: 0000000000000000 RSI: ffffffff8bc077c0 RDI: 00007f189158eec9 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81aa34ad R10: dffffc0000000000 R11: ffffffff81abbce0 R12: ffff888027343c80 R13: 0000000000000000 R14: 00007f189158eec9 R15: 1ffff92001616dbe FS: 00007f18924126c0(0000) GS:ffff888125e0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9fdd7b3ad8 CR3: 000000005b2ef000 CR4: 0000000000350ef0 Call Trace: __module_text_address kernel/module/main.c:3871 [inline] is_module_text_address+0x88/0x1e0 kernel/module/main.c:3846 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2515 [inline] slab_free mm/slub.c:6574 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6684 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] veth_xmit+0xb6a/0xe30 drivers/net/veth.c:356 __netdev_start_xmit include/linux/netdevice.h:5248 [inline] netdev_start_xmit include/linux/netdevice.h:5257 [inline] xmit_one net/core/dev.c:3845 [inline] dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4763 dev_queue_xmit include/linux/netdevice.h:3365 [inline] __bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153 ____bpf_clone_redirect net/core/filter.c:2478 [inline] bpf_clone_redirect+0x272/0x3d0 net/core/filter.c:2448 bpf_prog_53aa0f136d2aac90+0x62/0x6b bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] bpf_test_run+0x318/0x7b0 net/bpf/test_run.c:434 bpf_prog_test_run_skb+0xb4e/0x1550 net/bpf/test_run.c:1102 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4673 __sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6152 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline] __se_sys_bpf kernel/bpf/syscall.c:6242 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242 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: 0033:0x7f189158eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1892412038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f18917e5fa0 RCX: 00007f189158eec9 RDX: 0000000000000050 RSI: 0000200000000900 RDI: 000000000000000a RBP: 00007f1891611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f18917e6038 R14: 00007f18917e5fa0 R15: 00007ffded1e7f48