rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P2962/1:b..l
	(detected by 1, t=10502 jiffies, g=33925, q=504)
task:udevd           state:R  running task     stack:22720 pid: 2962 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:13 [inline]
RIP: 0010:lock_acquire+0xd6/0x4f0 kernel/locking/lockdep.c:5594
Code: 83 fb 08 0f 83 e2 02 00 00 89 d8 c1 e8 06 48 8d 3c c5 28 6c e4 8d be 08 00 00 00 e8 04 81 67 00 89 d8 48 0f a3 05 62 c2 81 0c <73> 0d e8 93 68 08 00 84 c0 0f 84 b9 02 00 00 48 c7 c0 c4 9f e4 8d
RSP: 0018:ffffc90002c279e0 EFLAGS: 00000257
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8162a9bc
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de46c28
RBP: ffffc90002c27b30 R08: dffffc0000000000 R09: fffffbfff1bc8d86
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000584f44
R13: dffffc0000000000 R14: 0000000000000000 R15: 000000005aa85520
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 pfn_valid include/linux/mmzone.h:1499 [inline]
 __virt_addr_valid+0x176/0x450 arch/x86/mm/physaddr.c:65
 check_heap_object mm/usercopy.c:228 [inline]
 __check_object_size+0xab/0x410 mm/usercopy.c:286
 check_object_size include/linux/thread_info.h:199 [inline]
 strncpy_from_user+0x99/0x370 lib/strncpy_from_user.c:137
 getname_flags+0xf5/0x4e0 fs/namei.c:149
 user_path_at_empty+0x2a/0x180 fs/namei.c:2882
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x106/0x3b0 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat fs/stat.c:405 [inline]
 __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f43d1fa65f4
RSP: 002b:00007ffe17ff9b98 EFLAGS: 00000202 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000561292bd66f0 RCX: 00007f43d1fa65f4
RDX: 00007ffe17ff9bb0 RSI: 00007f43d2043130 RDI: 000000000000000d
RBP: 0000561292c775f0 R08: 0000000000090800 R09: 0000561292bd6900
R10: 0000000000001000 R11: 0000000000000202 R12: 00007ffe17ff9bb0
R13: 00000000000000ff R14: 00005612923d11c4 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 9852 jiffies! g33925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26328 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570