syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10500 ticks this GP) idle=c1a/1/0x4000000000000002 softirq=11524/11524 fqs=2764 
	(t=10502 jiffies g=6557 q=464)
rcu: rcu_preempt kthread starved for 4974 jiffies! g6557 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 8319 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0
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+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:check_kcov_mode kernel/kcov.c:79 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:102
Code: d4 01 3b 00 5b 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 38 84 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 <83> fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84
RSP: 0018:ffffc90002287850 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff88808b762140
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea000282dd80
RBP: ffffc90002287878 R08: dffffc0000000000 R09: fffffbfff120248a
R10: fffffbfff120248a R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a9a814e8
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:92 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:109 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:166 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/generic.c:182 [inline]
RIP: 0010:check_memory_region+0x84/0x2e0 mm/kasan/generic.c:192
Code: 4d 29 ce 49 83 fe 10 7f 37 4d 85 f6 0f 84 a9 01 00 00 4c 89 cb 4c 29 d3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 45 0f b6 19 <45> 84 db 0f 85 09 02 00 00 49 ff c1 48 ff c3 75 eb e9 7b 01 00 00
RSP: 0000:ffffc90002287ad0 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff81a9941e
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8943d460
RBP: ffffc90002287af8 R08: dffffc0000000000 R09: fffffbfff1287a8c
R10: fffffbfff1287a8d R11: 0000000000000000 R12: 1ffffffff1287a8c
R13: dffffc0000000001 R14: 0000000000000001 R15: 0000000000000000
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:94
 test_bit include/asm-generic/bitops-instrumented.h:237 [inline]
 cpumask_test_cpu include/linux/cpumask.h:360 [inline]
 trace_mm_page_alloc+0x13e/0x1f0 include/trace/events/kmem.h:193
 __alloc_pages_nodemask+0x2e3/0x5d0 mm/page_alloc.c:4785
 alloc_pages_vma+0x4f7/0xd50 mm/mempolicy.c:2170
 alloc_zeroed_user_highpage_movable include/linux/highmem.h:208 [inline]
 do_anonymous_page+0x327/0x1610 mm/memory.c:3098
 handle_pte_fault mm/memory.c:3943 [inline]
 __handle_mm_fault mm/memory.c:4075 [inline]
 handle_mm_fault+0x1bce/0x2890 mm/memory.c:4112
 do_user_addr_fault+0x589/0xaf0 arch/x86/mm/fault.c:1441
 __do_page_fault+0xd3/0x1f0 arch/x86/mm/fault.c:1506
 do_page_fault+0x99/0xb0 arch/x86/mm/fault.c:1530
 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1203
RIP: 0033:0x45d02d
Code: 5b 5d f3 c3 66 0f 1f 84 00 00 00 00 00 48 c7 c0 ea ff ff ff 48 85 ff 0f 84 e0 8c fb ff 48 85 f6 0f 84 d7 8c fb ff 48 83 ee 10 <48> 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8
RSP: 002b:00007ffca5bde3d8 EFLAGS: 00010202
RAX: ffffffffffffffea RBX: 00007f4b96431700 RCX: 00007f4b96431700
RDX: 00000000003d0f00 RSI: 00007f4b96430db0 RDI: 0000000000411260
RBP: 00007ffca5bde5f0 R08: 00007f4b964319d0 R09: 00007f4b96431700
R10: 00007f4b96430dc0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffca5bde48f R14: 00007f4b964319c0 R15: 000000000075bf2c