INFO: task syz-executor.5:29746 blocked for more than 140 seconds. Not tainted 4.14.218-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28880 29746 7975 0x00000004 Call Trace: context_switch syzkaller/managers/linux-4-14/kernel/kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 syzkaller/managers/linux-4-14/kernel/kernel/sched/core.c:3384 schedule+0x8d/0x1b0 syzkaller/managers/linux-4-14/kernel/kernel/sched/core.c:3428 schedule_timeout+0x80a/0xe90 syzkaller/managers/linux-4-14/kernel/kernel/time/timer.c:1724 do_wait_for_common syzkaller/managers/linux-4-14/kernel/kernel/sched/completion.c:91 [inline] __wait_for_common syzkaller/managers/linux-4-14/kernel/kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 syzkaller/managers/linux-4-14/kernel/kernel/sched/completion.c:123 usb_start_wait_urb+0x125/0x440 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/message.c:61 usb_bulk_msg+0x1f6/0x500 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/message.c:252 proc_bulk+0x331/0x6d0 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/devio.c:1223 usbdev_do_ioctl+0x5b0/0x2b70 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/devio.c:2449 usbdev_ioctl+0x21/0x30 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/devio.c:2599 vfs_ioctl syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:46 [inline] file_ioctl syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:684 SYSC_ioctl syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x465b09 RSP: 002b:00007f17e75ee188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000020000040 RSI: 00000000c0185502 RDI: 0000000000000003 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffc42d2b74f R14: 00007f17e75ee300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7671: #0: (&p->pi_lock){-.-.}, at: [] __fdget_pos+0x1fb/0x2b0 syzkaller/managers/linux-4-14/kernel/fs/file.c:769 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1531 Comm: khungtaskd Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 syzkaller/managers/linux-4-14/kernel/lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 syzkaller/managers/linux-4-14/kernel/lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace syzkaller/managers/linux-4-14/kernel/./include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks syzkaller/managers/linux-4-14/kernel/kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 syzkaller/managers/linux-4-14/kernel/kernel/hung_task.c:274 kthread+0x30d/0x420 syzkaller/managers/linux-4-14/kernel/kernel/kthread.c:232 ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4605 Comm: systemd-journal Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a227a380 task.stack: ffff8880a2280000 RIP: 0010:do_syscall_64+0x3fd/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:298 RSP: 0018:ffff8880a2287f00 EFLAGS: 000000d7 RAX: ffff8880a227a380 RBX: ffff8880a227a380 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a227a388 RBP: ffff8880a2287f58 R08: ffff8880a227a380 R09: dffffc0000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000100 R13: ffff8880a2287fd0 R14: 1ffffffff11e1250 R15: 0000000000000000 FS: 00007fd0d1fca8c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd0c9ab4000 CR3: 00000000a238e000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fd0d1294303 RSP: 002b:00007fff2197b6f0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e8 RAX: 0000000000000001 RBX: 0000561bb25be1e0 RCX: 00007fd0d1294303 RDX: 0000000000000014 RSI: 00007fff2197b700 RDI: 0000000000000008 RBP: 00007fff2197b8f0 R08: 00007fff219a5000 R09: 000002b417515a4b R10: 00000000ffffffff R11: 0000000000000293 R12: 00007fff2197b700 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005bb0c2714f3f0 Code: 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e c0 00 00 00 83 63 08 f9 0f 1f 44 00 00 e8 3a ce 54 00 0f 00 2d 53 07 80 06 <48> 83 c4 28 5b 5d 41 5c 41 5d 41 5e e9 22 ce 54 00 e8 1d ce 54