INFO: task syz-executor.0:17710 blocked for more than 140 seconds. Not tainted 4.14.281-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28720 17710 8002 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 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: 0033:0x7f2770841109 RSP: 002b:00007f276f1b6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2770953f60 RCX: 00007f2770841109 RDX: 0000000020000040 RSI: 00000000c0185502 RDI: 0000000000000003 RBP: 00007f277089b08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4401856f R14: 00007f276f1b6300 R15: 0000000000022000 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/7700: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:819 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.281-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8 Comm: rcu_preempt Not tainted 4.14.281-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880b5420200 task.stack: ffff8880b5428000 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:796 [inline] RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x2d/0xc0 kernel/locking/spinlock.c:160 RSP: 0018:ffff8880b542fc48 EFLAGS: 00000282 RAX: 0000000000000282 RBX: 0000000000032480 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff88f805c0 RDI: ffffffff8bfea348 RBP: ffffffff8bfea348 R08: ffffffff8b9c42d0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff11016a85f99 R13: ffffffff88f805c0 R14: ffff8880b542fd18 R15: ffffffff8bfea348 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f05f3df3020 CR3: 0000000093a87000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_free lib/debugobjects.c:598 [inline] debug_object_free+0x52/0x320 lib/debugobjects.c:586 destroy_timer_on_stack kernel/time/timer.c:724 [inline] schedule_timeout+0x4c6/0xe90 kernel/time/timer.c:1751 rcu_gp_kthread+0xc0a/0x1e60 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: c0 80 98 f0 88 41 54 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 55 48 89 fd 80 3c 10 00 75 7f 48 83 3d 57 22 cc 01 00 74 71 9c 58 <0f> 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 49 89 c4 48 c7 c0 ---------------- Code disassembly (best guess): 0: c0 80 98 f0 88 41 54 rolb $0x54,0x4188f098(%rax) 7: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx e: fc ff df 11: 48 c1 e8 03 shr $0x3,%rax 15: 55 push %rbp 16: 48 89 fd mov %rdi,%rbp 19: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 1d: 75 7f jne 0x9e 1f: 48 83 3d 57 22 cc 01 cmpq $0x0,0x1cc2257(%rip) # 0x1cc227e 26: 00 27: 74 71 je 0x9a 29: 9c pushfq 2a: 58 pop %rax * 2b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 30: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 37: fc ff df 3a: 49 89 c4 mov %rax,%r12 3d: 48 rex.W 3e: c7 .byte 0xc7 3f: c0 .byte 0xc0