syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P29707/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=344461, q=438766 ncpus=2)
task:syz.1.8689      state:R  running task     stack:25584 pid:29707 tgid:29702 ppid:8907   task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1840/0x57a0 kernel/sched/core.c:7189
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x8e0 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x19c5/0x2550 arch/x86/kernel/unwind_orc.c:-1
Code: 0f b6 04 20 84 c0 0f 85 c5 0a 00 00 48 0f bf 03 49 01 c0 49 8d 56 40 4c 89 f7 4c 89 c6 e8 33 0e 00 00 84 c0 0f 84 4e 01 00 00 <48> bb 00 00 00 00 00 fc ff df 48 8b 44 24 10 0f b6 04 18 84 c0 0f
RSP: 0018:ffffc900055075a0 EFLAGS: 00000202
RAX: 1ffff92000aa0e01 RBX: ffffffff916a3968 RCX: 0000000000000001
RDX: ffffc90005507688 RSI: dffffc0000000000 RDI: ffffc90005507f38
RBP: 1ffffffff22d472d R08: ffffc90005507f38 R09: 0000000000000000
R10: ffffc90005507698 R11: fffff52000aa0ed5 R12: dffffc0000000000
R13: ffffffff916a3969 R14: ffffc90005507648 R15: ffffc90005507690
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x122/0x230 mm/page_owner.c:165
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1397 [inline]
 __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938
 vfree+0x1fd/0x330 mm/vmalloc.c:3472
 kcov_put kernel/kcov.c:444 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:543
 __fput+0x418/0xa50 fs/file_table.c:510
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:976
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1119
 get_signal+0x121b/0x12c0 kernel/signal.c:3038
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0xa9/0x6b0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f008039ce59
RSP: 002b:00007f007e5f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f0080616098 RCX: 00007f008039ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0080616098
RBP: 00007f0080616090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0080616128 R14: 00007f008073f960 R15: 00007f008073fa48
 </TASK>