syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6147/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=15669, q=783 ncpus=2)
task:syz.4.199       state:R  running task     stack:26448 pid:6147  tgid:6146  ppid:5230   flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 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:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:206
Code: 8b 3d 9c bc 95 0c 48 89 de 5b e9 23 87 5b 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 40 d7 03 00 65 8b 15 c0 60 70 7e f7 c2 00 01 ff 00
RSP: 0018:ffffc9000455fb18 EFLAGS: 00000246
RAX: ffffffff8baad536 RBX: 0000000000000000 RCX: 0000000000040000
RDX: 0000000000000004 RSI: ffffffff8ffe8790 RDI: 0000000000000003
RBP: ffffc9000455fc70 R08: 0000000000000005 R09: ffffffff8baad4fe
R10: 0000000000000004 R11: ffff88802f7cda00 R12: ffff88807b02e808
R13: 000055557c023fff R14: dffffc0000000000 R15: ffff88807b02e800
 ma_slots lib/maple_tree.c:762 [inline]
 mtree_lookup_walk lib/maple_tree.c:3712 [inline]
 mtree_load+0x496/0x940 lib/maple_tree.c:6333
 vma_lookup include/linux/mm.h:3483 [inline]
 do_pages_stat_array mm/migrate.c:2331 [inline]
 do_pages_stat mm/migrate.c:2402 [inline]
 kernel_move_pages mm/migrate.c:2489 [inline]
 __do_sys_move_pages mm/migrate.c:2500 [inline]
 __se_sys_move_pages+0x170f/0x1e60 mm/migrate.c:2495
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7d735779f9
RSP: 002b:00007f7d742d5048 EFLAGS: 00000246 ORIG_RAX: 0000000000000117
RAX: ffffffffffffffda RBX: 00007f7d73705f80 RCX: 00007f7d735779f9
RDX: 0000000020000080 RSI: 0000000000001efe RDI: 0000000000000000
RBP: 00007f7d735e58ee R08: 0000000020000040 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f7d73705f80 R15: 00007ffd1a7a5848
 </TASK>
rcu: rcu_preempt kthread starved for 10256 jiffies! g15669 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:26576 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </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:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111
sched: RT throttling activated