rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3193/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=268405, q=1523 ncpus=2)
task:syz.1.5765      state:R  running task     stack:24816 pid:3193  tgid:3192  ppid:1989   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1850/0x4c30 kernel/sched/core.c:6756
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5874
Code: 3c 3b 00 74 08 4c 89 f7 e8 95 f8 8a 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000470f720 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920008e1ef6 RCX: ffffc9000470f703
RDX: 0000000000000000 RSI: ffffffff8c0aa960 RDI: ffffffff8c5faee0
RBP: ffffc9000470f848 R08: ffffffff90197d77 R09: 1ffffffff2032fae
R10: dffffc0000000000 R11: fffffbfff2032faf R12: 1ffff920008e1ef0
R13: 0000000000000246 R14: ffffc9000470f7b0 R15: dffffc0000000000
 rcu_lock_release include/linux/rcupdate.h:347 [inline]
 rcu_read_unlock include/linux/rcupdate.h:880 [inline]
 page_ext_put+0xa3/0xc0 mm/page_ext.c:550
 page_table_check_free include/linux/page_table_check.h:41 [inline]
 free_pages_prepare mm/page_alloc.c:1128 [inline]
 free_unref_page+0xd53/0x1010 mm/page_alloc.c:2657
 vfree+0x186/0x2e0 mm/vmalloc.c:3382
 kcov_put kernel/kcov.c:439 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:535
 __fput+0x23c/0xa50 fs/file_table.c:450
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x16b2/0x1750 kernel/signal.c:3017
 arch_do_signal_or_restart+0x96/0x860 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]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f33c3f85d29
RSP: 002b:00007f33c4da40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f33c4175fa8 RCX: 00007f33c3f85d29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f33c4175fa8
RBP: 00007f33c4175fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f33c4175fac
R13: 0000000000000000 R14: 00007f33c429f940 R15: 00007f33c429fa28
 </TASK>