INFO: task syz-executor818:7961 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-executor818 D27848 7961 7960 0x00000004 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_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 usb_start_wait_urb+0x125/0x440 drivers/usb/core/message.c:61 usb_bulk_msg+0x1f6/0x500 drivers/usb/core/message.c:252 proc_bulk+0x331/0x6d0 drivers/usb/core/devio.c:1223 usbdev_do_ioctl+0x5b0/0x2b70 drivers/usb/core/devio.c:2449 usbdev_ioctl+0x21/0x30 drivers/usb/core/devio.c:2599 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x444209 RSP: 002b:00007ffefeb3d318 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 0000000000444209 RDX: 00000000200002c0 RSI: 00000000c0185502 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffefeb3d4b8 R09: 00007ffefeb3d4b8 R10: 00007ffefeb3cd90 R11: 0000000000000246 R12: 0000000000403520 R13: 431bde82d7b634db R14: 00000000004b2018 R15: 00000000004004a0 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 in:imklog/7668: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1533 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 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: 4615 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: ffff8880a1b06600 task.stack: ffff8880a1b08000 RIP: 0010:___bpf_prog_run+0x2f49/0x5a70 kernel/bpf/core.c:1134 RSP: 0018:ffff8880a1b0fa48 EFLAGS: 00000246 RAX: 0000000000000080 RBX: dffffc0000000000 RCX: ffff8880a1b0fe68 RDX: 1ffff11014361f6b RSI: ffffc900019c7030 RDI: ffffc900019c7059 RBP: ffff8880a1b0fb58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff878eff60 R13: 1ffff11014361f50 R14: ffffc900019c7058 R15: ffff8880a1b0fb58 FS: 00007fa2e86528c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa2e5a23000 CR3: 00000000a1f82000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: Code: 0f b6 04 18 38 d0 7f 08 84 c0 0f 85 47 18 00 00 41 0f b6 46 01 48 89 c2 83 e2 0f 4c 8d 7c d5 00 4c 89 fa 48 c1 ea 03 80 3c 1a 00 <0f> 85 a6 1d 00 00 c0 e8 04 49 8b 17 0f b6 c0 4c 8d 7c c5 00 4c