rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3649/1:b..l
	(detected by 0, t=10502 jiffies, g=5877, q=490 ncpus=2)
task:syz.0.7         state:R  running task     stack:24408 pid:3649  ppid:3546   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:820 [inline]
RIP: 0010:count_memcg_event_mm+0x330/0x410 include/linux/memcontrol.h:1099
Code: f6 79 bd ff 4c 8b 6c 24 18 eb 1f e8 ea 79 bd ff e8 65 0f be 08 4d 85 f6 74 84 e8 db 79 bd ff fb 49 be 00 00 00 00 00 fc ff df <e8> 0b 15 be 08 89 c3 31 ff 89 c6 e8 20 7d bd ff 85 db 74 10 e8 67
RSP: 0018:ffffc9000508f4c0 EFLAGS: 00000246
RAX: ffffffff81cd1a35 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc90003cc1000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc9000508f590 R08: ffffffff81cd19a5 R09: fffffbfff209384b
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000046
R13: ffffffff81cd17a0 R14: dffffc0000000000 R15: 1ffff92000a11e9c
 handle_mm_fault+0x15b/0x5340 mm/memory.c:5254
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166
Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 <f3> a4 31 c0 0f 01 ca c3 89 ca eb 0a 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc9000508f970 EFLAGS: 00050206
RAX: ffffffff84364701 RBX: 00007fffffffe000 RCX: 0000000000000e80
RDX: 0000000000001000 RSI: ffff88800fd86180 RDI: 0000000020907000
RBP: ffffc9000508faf8 R08: dffffc0000000000 R09: ffffed1001fb0e00
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000001000
R13: 0000000000000000 R14: 0000000020906e80 R15: ffff88800fd86000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout+0xd8/0x120 lib/iov_iter.c:170
 _copy_to_iter+0x4a6/0x1000 lib/iov_iter.c:527
 copy_page_to_iter+0xac/0x170 lib/iov_iter.c:725
 process_vm_rw_pages mm/process_vm_access.c:45 [inline]
 process_vm_rw_single_vec mm/process_vm_access.c:117 [inline]
 process_vm_rw_core mm/process_vm_access.c:215 [inline]
 process_vm_rw+0x886/0xcc0 mm/process_vm_access.c:283
 __do_sys_process_vm_readv mm/process_vm_access.c:295 [inline]
 __se_sys_process_vm_readv mm/process_vm_access.c:291 [inline]
 __x64_sys_process_vm_readv+0xdc/0xf0 mm/process_vm_access.c:291
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efeb3575bd9
RSP: 002b:00007efeb433b048 EFLAGS: 00000246 ORIG_RAX: 0000000000000136
RAX: ffffffffffffffda RBX: 00007efeb3703f60 RCX: 00007efeb3575bd9
RDX: 0000000000000002 RSI: 0000000020008400 RDI: 0000000000000007
RBP: 00007efeb35e4aa1 R08: 0000000000000286 R09: 0000000000000000
R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007efeb3703f60 R15: 00007ffc9041bfc8
 </TASK>
rcu: rcu_preempt kthread starved for 9726 jiffies! g5877 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:27256 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </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 acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572
sched: RT throttling activated