INFO: task syz-executor.2:17202 blocked for more than 140 seconds. Not tainted 4.14.202-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26960 17202 8030 0x80000002 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 device_lock include/linux/device.h:1081 [inline] usbdev_release+0x73/0x380 drivers/usb/core/devio.c:1066 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa08/0x27f0 kernel/exit.c:865 do_group_exit+0x100/0x2e0 kernel/exit.c:962 get_signal+0x38d/0x1ca0 kernel/signal.c:2423 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45de59 RSP: 002b:00007f2b7bc44cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000118bf28 RCX: 000000000045de59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118bf28 RBP: 000000000118bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffc802d0a7f R14: 00007f2b7bc459c0 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7755: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 2 locks held by agetty/7925: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write_lock drivers/tty/tty_io.c:885 [inline] #1: (&tty->atomic_write_lock){+.+.}, at: [] do_tty_write drivers/tty/tty_io.c:908 [inline] #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write+0x22d/0x740 drivers/tty/tty_io.c:1043 5 locks held by kworker/0:4/8074: #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+0x108/0x3dc0 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+0x190e/0x3dc0 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x15b/0x2970 drivers/usb/core/hub.c:4429 1 lock held by syz-executor.2/17202: #0: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #0: (&dev->mutex){....}, at: [] usbdev_release+0x73/0x380 drivers/usb/core/devio.c:1066 1 lock held by syz-executor.1/23651: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 1 lock held by syz-executor.3/23669: #0: (&type->s_umount_key#63/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#63/1){+.+.}, at: [] sget_userns+0x556/0xc10 fs/super.c:516 1 lock held by syz-executor.2/23685: #0: (&type->s_umount_key#63/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#63/1){+.+.}, at: [] sget_userns+0x556/0xc10 fs/super.c:516 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1531 Comm: khungtaskd Not tainted 4.14.202-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+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f 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: 5 Comm: kworker/u4:0 Not tainted 4.14.202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880b5ff2140 task.stack: ffff8880b5ff8000 RIP: 0010:native_apic_mem_write+0x0/0x10 arch/x86/include/asm/apic.h:95 RSP: 0018:ffff8880ba507fc0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff88cbd000 RCX: 0000000000000000 RDX: 1ffffffff1197a1e RSI: 0000000000000000 RDI: 00000000000000b0 RBP: 0000000000000000 R08: ffff88823fff7058 R09: ffff88823fff704f R10: ffff88823fff7057 R11: 000000c9b90e9b60 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005560577c1160 CR3: 0000000058ac2000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_eoi arch/x86/include/asm/apic.h:400 [inline] ack_APIC_irq arch/x86/include/asm/apic.h:444 [inline] entering_ack_irq arch/x86/include/asm/apic.h:636 [inline] smp_apic_timer_interrupt+0x88/0x5e0 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:99 [inline] RIP: 0010:__local_bh_enable_ip+0xed/0x170 kernel/softirq.c:192 RSP: 0018:ffff8880b5fffc50 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff11e121b RBX: 0000000000000201 RCX: 1ffff11016bfe542 RDX: dffffc0000000000 RSI: ffff8880b5ff29f0 RDI: ffff8880b5ff29c4 RBP: ffffffff8707ea3c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff87080550 R14: ffff8880619e19a8 R15: ffff888061931b40 spin_unlock_bh include/linux/spinlock.h:362 [inline] batadv_nc_purge_paths+0x20c/0x300 net/batman-adv/network-coding.c:479 batadv_nc_worker+0x628/0xc50 net/batman-adv/network-coding.c:727 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 Code: 38 d0 7c 04 84 d2 75 13 83 3d 2c 90 09 0a 01 7f 02 5d c3 89 ef 5d e9 e5 c7 fe ff 48 c7 c7 c0 c3 2c 8b e8 44 da 5d 00 eb df 66 90 <89> ff 89 b7 00 c0 5f ff c3 0f 1f 80 00 00 00 00 48 b8 00 00 00