rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4190/1:b..l
	(detected by 0, t=10502 jiffies, g=18813, q=205)
task:syz-executor    state:R  running task     stack:21808 pid: 4190 ppid:     1 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:check_region_inline mm/kasan/generic.c:172 [inline]
RIP: 0010:kasan_check_range+0x16/0x290 mm/kasan/generic.c:189
Code: 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 41 57 41 56 41 54 53 49 89 f8 <49> 01 f0 0f 82 0e 02 00 00 49 89 f8 49 c1 e8 2f 41 81 f8 ff ff 01
RSP: 0018:ffffc90002edf0d0 EFLAGS: 00000202
RAX: ffffffff819edb01 RBX: ffffea0001648df4 RCX: ffffffff819edc07
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0001648df4
RBP: ffffc90002edf230 R08: ffffea0001648df4 R09: 0000000000000003
R10: 0000000000000406 R11: 0000000000000000 R12: ffffc90002edf180
R13: fffffffffffffffe R14: ffffea0001648dc0 R15: dffffc0000000000
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_add_unless include/linux/atomic/atomic-instrumented.h:570 [inline]
 page_ref_add_unless include/linux/page_ref.h:166 [inline]
 __page_cache_add_speculative include/linux/pagemap.h:238 [inline]
 page_cache_get_speculative include/linux/pagemap.h:254 [inline]
 find_get_entry mm/filemap.c:1992 [inline]
 find_lock_entries+0x1f7/0xd70 mm/filemap.c:2092
 shmem_undo_range+0x29a/0x1930 mm/shmem.c:943
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145
 evict+0x4c9/0x8d0 fs/inode.c:647
 __dentry_kill+0x431/0x650 fs/dcache.c:586
 shrink_dentry_list+0x388/0x680 fs/dcache.c:1181
 shrink_dcache_parent+0xae/0x3d0 fs/dcache.c:-1
 do_one_tree+0x23/0xe0 fs/dcache.c:1662
 shrink_dcache_for_umount+0x65/0x110 fs/dcache.c:1679
 generic_shutdown_super+0x63/0x300 fs/super.c:447
 kill_anon_super fs/super.c:1089 [inline]
 kill_litter_super+0x72/0xa0 fs/super.c:1098
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x626/0x20c0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe03089660e
RSP: 002b:00007ffea534e3d8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000055557560c500 RCX: 00007fe03089660e
RDX: 0000000040000000 RSI: 00007ffea534e47c RDI: ffffffffffffffff
RBP: 00007ffea534e47c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000057
R13: 000055557561fa00 R14: 0000000000030f47 R15: 00007ffea534e4d0
 </TASK>
rcu: rcu_preempt kthread starved for 10163 jiffies! g18813 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27760 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729