9pnet_virtio: no channels available for device ./control INFO: rcu_sched self-detected stall on CPU 0-....: (124999 ticks this GP) idle=262/140000000000001/0 softirq=73662/73662 fqs=31218 (t=125000 jiffies g=41111 c=41110 q=337) NMI backtrace for cpu 0 CPU: 0 PID: 1714 Comm: syz-executor0 Not tainted 4.15.0-rc4+ #139 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+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] rcu_dump_cpu_stacks+0x186/0x1d5 kernel/rcu/tree.c:1459 print_cpu_stall kernel/rcu/tree.c:1608 [inline] check_cpu_stall.isra.64+0xbb8/0x15b0 kernel/rcu/tree.c:1676 __rcu_pending kernel/rcu/tree.c:3440 [inline] rcu_pending kernel/rcu/tree.c:3502 [inline] rcu_check_callbacks+0x256/0xd00 kernel/rcu/tree.c:2842 update_process_times+0x30/0x60 kernel/time/timer.c:1630 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1166 __run_hrtimer kernel/time/hrtimer.c:1211 [inline] __hrtimer_run_queues+0x349/0xe10 kernel/time/hrtimer.c:1275 hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1309 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:904 RIP: 0010:loop_set_fd drivers/block/loop.c:885 [inline] RIP: 0010:lo_ioctl+0x5de/0x1b70 drivers/block/loop.c:1358 RSP: 0018:ffff8801cb47fbd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11 RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffffff838ae21b RDX: 1ffff10039eb290c RSI: ffffc90003d67000 RDI: ffff8801cf594860 RBP: ffff8801cb47fc50 R08: ffffffff85f405c0 R09: 1ffff1003968ff2c R10: ffff8801cb47f928 R11: 0000000000000001 R12: ffff8801cf594780 R13: ffff8801d620a940 R14: ffff8801cf59f7c0 R15: ffff8801d620aa90 lo_compat_ioctl+0xab/0x140 drivers/block/loop.c:1556 compat_blkdev_ioctl+0x3ae/0x1840 block/compat_ioctl.c:406 C_SYSC_ioctl fs/compat_ioctl.c:1473 [inline] compat_SyS_ioctl+0x151/0x2a30 fs/compat_ioctl.c:1419 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:125 RIP: 0023:0xf7fbac79 RSP: 002b:00000000f77b608c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 0000000000004c00 RDX: 0000000000000014 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000