rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=6acc/1/0x4000000000000000 softirq=38431/38431 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=31065, q=1006 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5833 Comm: syz-executor Not tainted 6.15.0-syzkaller-07774-g90b83efa6701 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:204 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:242 [inline]
RIP: 0010:rb_erase+0x3e6/0xe60 lib/rbtree.c:443
Code: 4d 85 ed 75 7b 4c 89 e0 48 c1 e8 03 80 3c 28 00 74 08 4c 89 e7 e8 ba fa c3 f6 4d 8b 2c 24 41 83 e5 01 49 f7 dd 4d 21 fd eb 75 <48> 89 d8 48 c1 e8 03 80 3c 28 00 0f 84 a5 05 00 00 48 89 df e8 81
RSP: 0018:ffffc90000007ca8 EFLAGS: 00000046
RAX: 1ffff1100943be68 RBX: ffff8880b8627c10 RCX: dffffc0000000000
RDX: 0000000000010000 RSI: ffff8880b8627c10 RDI: ffff88804a1df348
RBP: dffffc0000000000 R08: ffffffff8fa0b1b7 R09: 1ffffffff1f41636
R10: dffffc0000000000 R11: fffffbfff1f41637 R12: ffff88804a1df340
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c66000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f837ea00218 CR3: 000000000df36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rb_erase_cached include/linux/rbtree.h:126 [inline]
 timerqueue_del+0xae/0x100 lib/timerqueue.c:57
 __remove_hrtimer kernel/time/hrtimer.c:1121 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1741 [inline]
 __hrtimer_run_queues+0x364/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:_static_cpu_has arch/x86/include/asm/cpufeature.h:101 [inline]
RIP: 0010:__nr_to_section include/linux/mmzone.h:1917 [inline]
RIP: 0010:__pfn_to_section include/linux/mmzone.h:2059 [inline]
RIP: 0010:pfn_valid+0x26/0x490 include/linux/mmzone.h:2115
Code: 90 90 90 90 55 41 57 41 56 41 55 41 54 53 49 89 fe e8 3e ba 91 ff e9 f3 03 00 00 e8 34 ba 91 ff 49 bc 00 00 00 00 00 fc ff df <e9> 24 04 00 00 e8 20 ba 91 ff 48 c7 c0 60 d4 ac 99 48 c1 e8 03 42
RSP: 0018:ffffc9000454f338 EFLAGS: 00000293
RAX: ffffffff822e44ce RBX: 1ffffd400026ac23 RCX: ffff88807e00bc00
RDX: 0000000000000000 RSI: 000000000004d584 RDI: 0000000400000000
RBP: ffffc9000454f670 R08: ffffea0001356107 R09: 1ffffd400026ac20
R10: dffffc0000000000 R11: fffff9400026ac21 R12: dffffc0000000000
R13: dffffc0000000000 R14: 000000000004d584 R15: 800000004d584007
 page_table_check_clear+0x21/0x700 mm/page_table_check.c:70
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 get_and_clear_full_ptes include/linux/pgtable.h:714 [inline]
 zap_present_folio_ptes mm/memory.c:1501 [inline]
 zap_present_ptes mm/memory.c:1586 [inline]
 do_zap_pte_range mm/memory.c:1687 [inline]
 zap_pte_range mm/memory.c:1731 [inline]
 zap_pmd_range mm/memory.c:1823 [inline]
 zap_pud_range mm/memory.c:1852 [inline]
 zap_p4d_range mm/memory.c:1873 [inline]
 unmap_page_range+0x32fd/0x4580 mm/memory.c:1894
 unmap_vmas+0x25d/0x3c0 mm/memory.c:1984
 exit_mmap+0x245/0xba0 mm/mmap.c:1284
 __mmput+0x118/0x420 kernel/fork.c:1381
 exit_mm+0x1da/0x2c0 kernel/exit.c:595
 do_exit+0x864/0x2550 kernel/exit.c:947
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1108
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc89d5c11e5
Code: Unable to access opcode bytes at 0x7fc89d5c11bb.
RSP: 002b:00007ffff80ad790 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 0000000000000283 RCX: 00007fc89d5c11e5
RDX: 00007ffff80ad7d0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffff80ad83c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000000e5
R13: 0000000000000018 R14: 000000000003555c R15: 00007ffff80ad890
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g31065 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=10385
rcu: rcu_preempt kthread starved for 10502 jiffies! g31065 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27320 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
 __schedule_loop kernel/sched/core.c:6859 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6874
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>