syzbot

INFO: rcu_sched self-detected stall on CPU
	0-....: (124999 ticks this GP) idle=a76/1/4611686018427387906 softirq=44174/44174 fqs=31158 
	 (t=125000 jiffies g=23917 c=23916 q=835)
NMI backtrace for cpu 0
CPU: 0 PID: 12307 Comm: syz-executor1 Not tainted 4.16.0+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 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+0x175/0x1c2 kernel/rcu/tree.c:1376
 print_cpu_stall kernel/rcu/tree.c:1525 [inline]
 check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
 __rcu_pending kernel/rcu/tree.c:3356 [inline]
 rcu_pending kernel/rcu/tree.c:3401 [inline]
 rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0xa0/0x180 kernel/time/tick-sched.c:171
 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1179
 __run_hrtimer kernel/time/hrtimer.c:1337 [inline]
 __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1399
 hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1457
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x38/0x50 kernel/kcov.c:107
RSP: 0018:ffff88018945f648 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc900044f3000
RDX: 0000000000000002 RSI: ffffffff832eeec4 RDI: 0000000000000005
RBP: ffff88018945f648 R08: ffff8801d9fd4580 R09: ffff8801ad1381e8
R10: ffffed0035a2703d R11: ffff8801ad1381ef R12: ffffffffffffff00
R13: ffffffffffffffff R14: ffff8801ad1381e8 R15: 0000000000000000
 __bitmap_set+0x114/0x140 lib/bitmap.c:274
 bitmap_set include/linux/bitmap.h:375 [inline]
 __bitmap_parselist+0x4eb/0x5d0 lib/bitmap.c:616
 bitmap_parselist+0x3a/0x50 lib/bitmap.c:628
 cpulist_parse include/linux/cpumask.h:639 [inline]
 update_cpumask kernel/cgroup/cpuset.c:974 [inline]
 cpuset_write_resmask+0x1b77/0x2e80 kernel/cgroup/cpuset.c:1724
 cgroup_file_write+0x317/0x820 kernel/cgroup/cgroup.c:3429
 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316
 __vfs_write+0x10b/0x880 fs/read_write.c:485
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0xf9/0x250 fs/read_write.c:598
 SYSC_write fs/read_write.c:610 [inline]
 SyS_write+0x24/0x30 fs/read_write.c:607
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455259
RSP: 002b:00007f21379c0c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f21379c16d4 RCX: 0000000000455259
RDX: 0000000000000002 RSI: 0000000020000040 RDI: 0000000000000016
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006bc R14: 00000000006fd240 R15: 0000000000000000
INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 0-... } 126843 jiffies s: 3933 root: 0x1/.
blocking rcu_node structures:
Task dump for CPU 0:
syz-executor1   R  running task    24280 12307   4517 0x0000000c
Call Trace: