INFO: rcu_sched self-detected stall on CPU
	1-...!: (124995 ticks this GP) idle=936/1/4611686018427387906 softirq=16694/16698 fqs=4 
	 (t=125000 jiffies g=5599 c=5598 q=97)
rcu_sched kthread starved for 124984 jiffies! g5599 c5598 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_sched       R  running task    29712     8      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2800 [inline]
 __schedule+0x850/0x1e10 kernel/sched/core.c:3376
 schedule+0x7c/0x1a0 kernel/sched/core.c:3435
 schedule_timeout+0x46d/0x1150 kernel/time/timer.c:1816
 rcu_gp_kthread+0xbfd/0x19f0 kernel/rcu/tree.c:2231
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524
NMI backtrace for cpu 1
CPU: 1 PID: 5068 Comm: syz-executor7 Not tainted 4.15.0-rc6-next-20180108+ #90
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x137/0x198 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+0x186/0x1d7 kernel/rcu/tree.c:1375
 print_cpu_stall kernel/rcu/tree.c:1524 [inline]
 check_cpu_stall kernel/rcu/tree.c:1592 [inline]
 __rcu_pending kernel/rcu/tree.c:3362 [inline]
 rcu_pending kernel/rcu/tree.c:3424 [inline]
 rcu_check_callbacks+0x1a64/0x1de0 kernel/rcu/tree.c:2764
 update_process_times+0x30/0x60 kernel/time/timer.c:1628
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162
 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1176
 __run_hrtimer kernel/time/hrtimer.c:1210 [inline]
 __hrtimer_run_queues+0x2c8/0xb50 kernel/time/hrtimer.c:1274
 hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1308
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0xc9/0x4c0 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:920
 </IRQ>
RIP: 0010:cvt_s16_to_native sound/core/oss/mulaw.c:164 [inline]
RIP: 0010:mulaw_decode+0x4ff/0x740 sound/core/oss/mulaw.c:195
RSP: 0018:ffff8801c5d0f948 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
RAX: 0000000000000007 RBX: ffffc9000137459e RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffff8801c5d0fa00 RDI: ffff8801cd5c20a4
RBP: ffff8801c5d0fa68 R08: fffff52000254368 R09: fffff52000254368
R10: 0000000000000001 R11: fffff52000254367 R12: 0000000000000002
R13: ffffc900012a1b3c R14: ffff8801cd5c2000 R15: dffffc0000000000
 mulaw_transfer+0x222/0x270 sound/core/oss/mulaw.c:273
 snd_pcm_plug_write_transfer+0x22c/0x390 sound/core/oss/pcm_plugin.c:619
 snd_pcm_oss_write2+0x22e/0x3c0 sound/core/oss/pcm_oss.c:1310
 snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1371 [inline]
 snd_pcm_oss_write+0x4c1/0x690 sound/core/oss/pcm_oss.c:2645
 __vfs_write+0xef/0x740 fs/read_write.c:480
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xd4/0x1a0 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f7859a3bc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 00000000fffffee4 RSI: 0000000020735ee0 RDI: 0000000000000013
RBP: 0000000000000476 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4bb0
R13: 00000000ffffffff R14: 00007f7859a3c6d4 R15: 0000000000000000