rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=efb4/1/0x4000000000000000 softirq=31188/31188 fqs=0
	(detected by 1, t=10502 jiffies, g=41121, q=1186 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8273 Comm: syz.2.1241 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_acquire+0x6/0x490 kernel/locking/lockdep.c:5630
Code: e9 35 fb ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 65 8b 05 f1 7d 9f 7e a9 00 ff ff 00 0f 95 c0 c3 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 4c 89 4c 24
RSP: 0018:ffffc90000007c60 EFLAGS: 00000046
RAX: 0000000000010002 RBX: ffff8880b8e2a580 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b8e2a598
RBP: ffffc90000007c68 R08: 0000000000000001 R09: 0000000000000000
R10: fffffbfff1c3eea6 R11: 1ffffffff1c3eea5 R12: ffff88807616a340
R13: dffffc0000000000 R14: 1ffff92000000f90 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c37c8d4 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1756 [inline]
 __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1816
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:page_ext_get+0x279/0x2a0 mm/page_ext.c:165
Code: 98 8a be 35 03 00 00 48 c7 c2 a0 f0 98 8a e8 be 92 88 ff e8 79 c8 90 ff 48 c7 c7 e0 ab b2 8c 48 89 de e8 1a 65 88 ff 45 31 ff <4c> 89 f8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 14 c2 a5 ff e9 d9 fe
RSP: 0018:ffffc9000bfb7428 EFLAGS: 00000293
RAX: ffffffff81db0dce RBX: ffffffff81db0c0e RCX: ffff88802ca81dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: dffffc0000000001
R13: 0000000000000160 R14: 00000000019ddc00 R15: ffff88801b11dc00
 page_table_check_clear+0x4a/0x6b0 mm/page_table_check.c:71
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 zap_pte_range mm/memory.c:1435 [inline]
 zap_pmd_range mm/memory.c:1574 [inline]
 zap_pud_range mm/memory.c:1603 [inline]
 zap_p4d_range mm/memory.c:1624 [inline]
 unmap_page_range+0x1924/0x2500 mm/memory.c:1645
 unmap_vmas+0x22c/0x330 mm/memory.c:1730
 exit_mmap+0x1cc/0x8e0 mm/mmap.c:3250
 __mmput+0x118/0x3c0 kernel/fork.c:1200
 exit_mm+0x1e6/0x2c0 kernel/exit.c:565
 do_exit+0x8c1/0x2400 kernel/exit.c:867
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2c4b78eba9
Code: Unable to access opcode bytes at 0x7f2c4b78eb7f.
RSP: 002b:00007f2c4c6900e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f2c4b9d5fa8 RCX: 00007f2c4b78eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2c4b9d5fa8
RBP: 00007f2c4b9d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2c4b9d6038 R14: 00007ffdc343f970 R15: 00007ffdc343fa58
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g41121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=16277
rcu: rcu_preempt kthread starved for 10502 jiffies! g41121 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:27200 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8273 Comm: syz.2.1241 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_acquire+0xb3/0x7c50 kernel/locking/lockdep.c:4916
Code: f2 f2 f2 00 00 00 4a 89 44 01 0b 42 c7 44 01 17 f3 f3 f3 f3 48 89 8c 24 f0 00 00 00 42 c6 44 01 1b f3 65 4c 8b 25 5d 77 9f 7e <48> c7 c0 e4 a9 1f 8e 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 53 65
RSP: 0018:ffffc90000007860 EFLAGS: 00000806
RAX: 000000f2f2f2f2f2 RBX: ffffffff96edea50 RCX: 1ffff92000000f30
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff96edea50
RBP: ffffc90000007ab0 R08: dffffc0000000000 R09: 0000000000000001
R10: fffffbfff1c3eea6 R11: 1ffffffff1c3eea5 R12: ffff88802ca81dc0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c37c8d4 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0x6a/0x490 lib/debugobjects.c:698
 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline]
 debug_activate kernel/time/hrtimer.c:503 [inline]
 enqueue_hrtimer+0x30/0x3f0 kernel/time/hrtimer.c:1110
 __run_hrtimer kernel/time/hrtimer.c:1769 [inline]
 __hrtimer_run_queues+0x68e/0xd60 kernel/time/hrtimer.c:1816
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:page_ext_get+0x279/0x2a0 mm/page_ext.c:165
Code: 98 8a be 35 03 00 00 48 c7 c2 a0 f0 98 8a e8 be 92 88 ff e8 79 c8 90 ff 48 c7 c7 e0 ab b2 8c 48 89 de e8 1a 65 88 ff 45 31 ff <4c> 89 f8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 14 c2 a5 ff e9 d9 fe
RSP: 0018:ffffc9000bfb7428 EFLAGS: 00000293
RAX: ffffffff81db0dce RBX: ffffffff81db0c0e RCX: ffff88802ca81dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: dffffc0000000001
R13: 0000000000000160 R14: 00000000019ddc00 R15: ffff88801b11dc00
 page_table_check_clear+0x4a/0x6b0 mm/page_table_check.c:71
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 zap_pte_range mm/memory.c:1435 [inline]
 zap_pmd_range mm/memory.c:1574 [inline]
 zap_pud_range mm/memory.c:1603 [inline]
 zap_p4d_range mm/memory.c:1624 [inline]
 unmap_page_range+0x1924/0x2500 mm/memory.c:1645
 unmap_vmas+0x22c/0x330 mm/memory.c:1730
 exit_mmap+0x1cc/0x8e0 mm/mmap.c:3250
 __mmput+0x118/0x3c0 kernel/fork.c:1200
 exit_mm+0x1e6/0x2c0 kernel/exit.c:565
 do_exit+0x8c1/0x2400 kernel/exit.c:867
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2c4b78eba9
Code: Unable to access opcode bytes at 0x7f2c4b78eb7f.
RSP: 002b:00007f2c4c6900e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f2c4b9d5fa8 RCX: 00007f2c4b78eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2c4b9d5fa8
RBP: 00007f2c4b9d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2c4b9d6038 R14: 00007ffdc343f970 R15: 00007ffdc343fa58
 </TASK>