INFO: task kworker/0:4:9168 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready kworker/0:4 D26336 9168 2 0x80000000 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 usb_kill_urb.part.0+0x197/0x220 drivers/usb/core/urb.c:697 usb_kill_urb+0x7c/0x90 drivers/usb/core/urb.c:692 usb_start_wait_urb+0x252/0x4c0 drivers/usb/core/message.c:63 usb_internal_control_msg drivers/usb/core/message.c:101 [inline] usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:152 usb_get_descriptor+0xc5/0x1b0 drivers/usb/core/message.c:654 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready usb_get_device_descriptor+0x81/0xf0 drivers/usb/core/message.c:926 hub_port_init+0x74b/0x3120 drivers/usb/core/hub.c:4799 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready hub_port_connect drivers/usb/core/hub.c:5070 [inline] hub_port_connect_change drivers/usb/core/hub.c:5253 [inline] port_event drivers/usb/core/hub.c:5361 [inline] hub_event+0x1ccd/0x44a0 drivers/usb/core/hub.c:5441 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 2 locks held by kworker/u4:2/35: 1 lock held by khungtaskd/1570: #0: 00000000b00fb6d1 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7826: #0: 00000000918ae0b7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 4 locks held by syz-executor.2/8148: #0: 00000000fe8840af (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #0: 00000000fe8840af (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready #1: 00000000b00fb6d1 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 00000000b00fb6d1 (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready #2: 000000009c94917c (pool_lock){-.-.}, at: __free_object+0x17/0x1e0 lib/debugobjects.c:251 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready #3: 0000000065b22fef (&obj_hash[i].lock){-.-.}, at: debug_object_assert_init lib/debugobjects.c:676 [inline] #3: 0000000065b22fef (&obj_hash[i].lock){-.-.}, at: debug_object_assert_init+0xfd/0x2e0 lib/debugobjects.c:665 5 locks held by kworker/0:4/9168: #0: 000000004db5029b ((wq_completion)"usb_hub_wq"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready #1: 00000000de37e64e ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready #2: 00000000d85dd623 (&dev->mutex){....}, at: device_lock include/linux/device.h:1174 [inline] #2: 00000000d85dd623 (&dev->mutex){....}, at: hub_event+0x11e/0x44a0 drivers/usb/core/hub.c:5387 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready #3: 00000000975d125d (&port_dev->status_lock){+.+.}, at: usb_lock_port drivers/usb/core/hub.c:2983 [inline] #3: 00000000975d125d (&port_dev->status_lock){+.+.}, at: hub_port_connect drivers/usb/core/hub.c:5069 [inline] #3: 00000000975d125d (&port_dev->status_lock){+.+.}, at: hub_port_connect_change drivers/usb/core/hub.c:5253 [inline] #3: 00000000975d125d (&port_dev->status_lock){+.+.}, at: port_event drivers/usb/core/hub.c:5361 [inline] #3: 00000000975d125d (&port_dev->status_lock){+.+.}, at: hub_event+0x1cb8/0x44a0 drivers/usb/core/hub.c:5441 #4: 0000000022bd926b (hcd->address0_mutex){+.+.}, at: hub_port_init+0x1b9/0x3120 drivers/usb/core/hub.c:4578 2 locks held by agetty/15220: #0: 000000000fe094a0 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000006d66a532 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 11203 Comm: kworker/u4:9 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: phy13 ieee80211_iface_work RIP: 0010:ieee80211_iface_work+0x5bf/0x8a0 net/mac80211/iface.c:1341 Code: 00 e9 e1 fc ff ff e8 d0 0e c7 f9 48 8b 7c 24 08 48 89 ee e8 93 82 11 00 e9 ca fc ff ff e8 b9 0e c7 f9 48 8b 7c 24 08 48 89 ee fc b8 ff ff e9 b3 fc ff ff 83 fb 0b 0f 85 7a fe ff ff e8 99 0e RSP: 0018:ffff888052f47cd8 EFLAGS: 00000293 RAX: ffff8880a0ef2100 RBX: ffff88804f4c7228 RCX: ffffffff879b734b RDX: 0000000000000000 RSI: ffff88809a2d23c0 RDI: ffff88804f4c6980 RBP: ffff88809a2d23c0 R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000080 R14: ffff88804f529d00 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002025c000 CR3: 000000009cc4a000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e9 e1 fc ff ff jmpq 0xfffffce6 5: e8 d0 0e c7 f9 callq 0xf9c70eda a: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi f: 48 89 ee mov %rbp,%rsi 12: e8 93 82 11 00 callq 0x1182aa 17: e9 ca fc ff ff jmpq 0xfffffce6 1c: e8 b9 0e c7 f9 callq 0xf9c70eda 21: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi 26: 48 89 ee mov %rbp,%rsi * 29: e8 fc b8 ff ff callq 0xffffb92a <-- trapping instruction 2e: e9 b3 fc ff ff jmpq 0xfffffce6 33: 83 fb 0b cmp $0xb,%ebx 36: 0f 85 7a fe ff ff jne 0xfffffeb6 3c: e8 .byte 0xe8 3d: 99 cltd 3e: 0e (bad)