rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5805/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=14389, q=1382594 ncpus=2)
task:syz-executor    state:R  running task     stack:23688 pid:5805  tgid:5805  ppid:5803   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6911
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_cmp8+0x0/0x20 kernel/kcov.c:293
Code: 0c 24 89 f2 89 fe bf 04 00 00 00 e9 ea fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe
RSP: 0018:ffffc90004107bf8 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000010 RCX: ffffffff828273fa
RDX: ffff88807c1d8000 RSI: 0000000000000000 RDI: 0000000000001000
RBP: 0000000000001000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffea0002128c00 R15: 0000000000000000
 __nr_to_section+0x3e/0x100 include/linux/mmzone.h:1972
 __pfn_to_section include/linux/mmzone.h:2114 [inline]
 lookup_page_ext+0x46/0x100 mm/page_ext.c:255
 page_ext_iter_begin include/linux/page_ext.h:133 [inline]
 __page_table_check_zero+0xe1/0x410 mm/page_table_check.c:139
 page_table_check_free include/linux/page_table_check.h:46 [inline]
 __free_pages_prepare mm/page_alloc.c:1434 [inline]
 __free_frozen_pages+0x7f1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4873
 alloc_filename fs/namei.c:142 [inline]
 do_getname+0x35/0x390 fs/namei.c:182
 getname_flags fs/namei.c:225 [inline]
 class_filename_flags_constructor include/linux/fs.h:2541 [inline]
 user_path_at+0x26/0x60 fs/namei.c:3642
 ksys_umount fs/namespace.c:2062 [inline]
 __do_sys_umount fs/namespace.c:2070 [inline]
 __se_sys_umount fs/namespace.c:2068 [inline]
 __x64_sys_umount+0x10a/0x1a0 fs/namespace.c:2068
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc876f9da57
RSP: 002b:00007ffe27ae9dd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc876f9da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe27ae9e90
RBP: 00007ffe27ae9e90 R08: 00007ffe27aeae90 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe27aeaf20
R13: 00007fc877032048 R14: 000000000002ae02 R15: 00007ffe27aeaf60
 </TASK>