rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6427/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=13825, q=571 ncpus=2)
task:syz.0.151       state:R  running task     stack:25720 pid:6427  tgid:6427  ppid:5815   task_flags:0x40044c flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_is_watching+0x67/0xb0 kernel/rcu/tree.c:737
Code: 89 f7 e8 9c ad 78 00 48 c7 c3 58 cb 73 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 49 87 cb 10 <74> 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 cc cc cc cc cc e8 e1 6b
RSP: 0018:ffffc90003ddf598 EFLAGS: 00000286
RAX: 00000000001cef84 RBX: ffff8880b8832b58 RCX: a10837e9fcd30600
RDX: 0000000000000001 RSI: ffffffff8bc122e0 RDI: ffffffff8bc122a0
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171ca05 R12: 1ffff920007bbed1
R13: ffffc90003ddf6c0 R14: ffffffff8d95cc20 R15: dffffc0000000000
 rcu_read_lock include/linux/rcupdate.h:842 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd4/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf7/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2721
 vfree+0x1a6/0x330 mm/vmalloc.c:3384
 kcov_put kernel/kcov.c:439 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:535
 __fput+0x449/0xa70 fs/file_table.c:465
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x8d6/0x2550 kernel/exit.c:953
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x125e/0x1310 kernel/signal.c:3034
 arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:231
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0033:0x7f1cc7067db0
RSP: 002b:00007ffcbf63a600 EFLAGS: 00000206
RAX: 00007f1cc6ab0950 RBX: 00007f1cc6aacb28 RCX: ffffffff820d1d94
RDX: ffffffff820d1d94 RSI: ffffffff820d1d94 RDI: 00007f1cc6ab18c8
RBP: 00007f1cc6aab440 R08: 00007f1cc6aae680 R09: 00007f1cc73a2000
R10: 00007f1cc67ff008 R11: 0000000000000004 R12: 00007f1cc6aab438
R13: 000000000000001a R14: 00007ffcbf63a7b8 R15: 00007f1cc67ff008
 </TASK>