INFO: task kworker/0:3:7981 blocked for more than 140 seconds. Not tainted 4.14.232-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D26720 7981 2 0x80000000 Workqueue: usb_hub_wq hub_event MTD: Attempt to mount non-MTD device "/dev/loop4" romfs: Mounting image 'rom 5f663c08' through the block layer Call Trace: MTD: Attempt to mount non-MTD device "/dev/loop3" MTD: Attempt to mount non-MTD device "/dev/loop0" romfs: Mounting image 'rom 5f663c08' through the block layer romfs: Mounting image 'rom 5f663c08' through the block layer context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 usb_kill_urb.part.0+0x125/0x190 drivers/usb/core/urb.c:691 usb_kill_urb+0x7c/0x90 drivers/usb/core/urb.c:686 usb_start_wait_urb+0x209/0x440 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x302/0x450 drivers/usb/core/message.c:151 hub_port_init+0xfdc/0x2970 drivers/usb/core/hub.c:4555 hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x18fd/0x3d70 drivers/usb/core/hub.c:5274 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by syz-executor.0/7956: #0: (rcu_preempt_state.exp_mutex){+.+.}, at: [] exp_funnel_lock kernel/rcu/tree_exp.h:272 [inline] #0: (rcu_preempt_state.exp_mutex){+.+.}, at: [] _synchronize_rcu_expedited+0x2c2/0x770 kernel/rcu/tree_exp.h:596 1 lock held by syz-executor.3/7959: #0: (rcu_preempt_state.exp_mutex){+.+.}, at: [] exp_funnel_lock kernel/rcu/tree_exp.h:305 [inline] #0: (rcu_preempt_state.exp_mutex){+.+.}, at: [] _synchronize_rcu_expedited+0x32d/0x770 kernel/rcu/tree_exp.h:596 1 lock held by syz-executor.4/7962: #0: (tasklist_lock){.+.+}, at: [] release_task+0x14d/0x1380 kernel/exit.c:198 5 locks held by kworker/0:3/7981: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3d70 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x18e8/0x3d70 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x15b/0x2970 drivers/usb/core/hub.c:4429 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4606 Comm: systemd-journal Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a21043c0 task.stack: ffff8880a2108000 RIP: 0010:__orc_find+0x94/0xf0 arch/x86/kernel/unwind_orc.c:56 RSP: 0018:ffff8880a210f6f8 EFLAGS: 00000287 RAX: ffffffff81864bc6 RBX: ffffffff8a196f4c RCX: ffffffff81864c25 RDX: 0000000000000000 RSI: ffffffff8a72b83c RDI: ffffffff8a196f4c RBP: ffffffff8a196f50 R08: ffffffff8a72b83c R09: ffffffff8a72b842 R10: 00000000000202be R11: 0000000000066071 R12: ffffffff8a196f4c R13: ffffffff8a196f4c R14: ffffffff8a196f4c R15: dffffc0000000000 FS: 00007fc985b778c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc9830a1000 CR3: 00000000a21a2000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:118 [inline] unwind_next_frame+0x59a/0x17d0 arch/x86/kernel/unwind_orc.c:348 __save_stack_trace+0x90/0x160 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] aa_alloc_file_ctx security/apparmor/include/file.h:60 [inline] apparmor_file_alloc_security+0x129/0x800 security/apparmor/lsm.c:431 security_file_alloc+0x66/0xa0 security/security.c:874 get_empty_filp+0x15c/0x3e0 fs/file_table.c:129 path_openat+0x84/0x2970 fs/namei.c:3545 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fc985106840 RSP: 002b:00007fff8d9905f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fff8d990900 RCX: 00007fc985106840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000562d581dfcd0 RBP: 000000000000000d R08: 000000000000ffc0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000562d581d2040 R14: 00007fff8d9908c0 R15: 0000562d581dfeb0 Code: 03 42 0f b6 14 38 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 48 48 63 03 48 01 d8 48 39 c1 73 b0 4c 8d 63 fc 49 39 ec 73 b3 <4d> 29 ee 49 c1 fe 02 4b 8d 04 76 48 8d 04 46 48 83 c4 10 5b 5d