syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9859/1:b..l
	(detected by 0, t=10502 jiffies, g=56869, q=33 ncpus=2)
task:modprobe        state:R  running task     stack:25152 pid:9859  ppid:8829   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__set_page_owner_handle+0xb6/0x3c0 mm/page_owner.c:168
Code: 24 10 89 de e8 4b 55 a7 ff 44 39 f3 0f 84 d8 02 00 00 48 8b 1d 6b af e9 0a 49 8d 7c 1f 08 48 89 f8 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 da 01 00 00 4c 01 fb 8b 44 24 08 89 43 08 48 89 d8 48
RSP: 0018:ffffc900033974f8 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000000
RDX: ffff888077153b80 RSI: 0000000000000002 RDI: ffff88801b931710
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88801b931700
 __set_page_owner+0x41/0x60 mm/page_owner.c:195
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 alloc_slab_page+0x5d/0x160 mm/slub.c:1799
 allocate_slab mm/slub.c:1944 [inline]
 new_slab+0x87/0x2c0 mm/slub.c:1997
 ___slab_alloc+0xbc6/0x1230 mm/slub.c:3154
 kmem_cache_alloc_bulk+0x1a3/0x4e0 mm/slub.c:3856
 mt_alloc_bulk lib/maple_tree.c:157 [inline]
 mas_alloc_nodes+0x449/0x890 lib/maple_tree.c:1299
 mas_node_count_gfp lib/maple_tree.c:1359 [inline]
 mas_preallocate+0x161/0x3c0 lib/maple_tree.c:5807
 __mmap_region mm/mmap.c:2765 [inline]
 mmap_region+0xd8a/0x1c70 mm/mmap.c:2916
 do_mmap+0x958/0xfd0 mm/mmap.c:1436
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f458ff08242
RSP: 002b:00007ffcc9db5f78 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f458fee0000 RCX: 00007f458ff08242
RDX: 0000000000000003 RSI: 0000000000004000 RDI: 00007f458fee0000
RBP: 0000000000000812 R08: 0000000000000000 R09: 00000000000be000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffcc9db6038
R13: 00007f458fee40c0 R14: 00007ffcc9db6380 R15: 00000fff993b6bf2
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10458 jiffies! g56869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=25458
rcu: rcu_preempt kthread starved for 10464 jiffies! g56869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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:741