syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 GPs behind) idle=010c/1/0x4000000000000000 softirq=13034/13035 fqs=5249
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:        0          0            0
rcu: 	cputime:        0          0            0   ==> 52510(ms)
rcu: 	(detected by 1, t=10502 jiffies, g=12381, q=574 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5922 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count_add+0x42/0x1a0 kernel/sched/core.c:5848
Code: e9 96 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 eb 00 00 00 83 3d 1e 47 8e 15 00 75 07 65 8b 05 5d 48 a8 7e 65 01 3d 56 48 a8 7e <48> c7 c0 80 b4 e9 96 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e6 00
RSP: 0018:ffffc90000007be0 EFLAGS: 00000086
RAX: 0000000080010002 RBX: ffffffff9712fb38 RCX: ffffffff96e9b403
RDX: 0000000000000005 RSI: ffffffff8aaace60 RDI: 0000000000000001
RBP: ffffc90000007c98 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000802 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003c80 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:109 [inline]
 _raw_spin_lock_irqsave+0x8d/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709
 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
 debug_activate kernel/time/hrtimer.c:505 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1108
 __run_hrtimer kernel/time/hrtimer.c:1767 [inline]
 __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:page_table_check_clear+0x26e/0x6a0 mm/page_table_check.c:90
Code: ee e8 a6 bb 9d ff 85 ed 0f 85 8d 01 00 00 49 8d 7c 24 04 be 04 00 00 00 e8 af 27 f5 ff 41 bd ff ff ff ff f0 45 0f c1 6c 24 04 <41> 8d 75 ff 31 ff e8 77 bb 9d ff 41 ff cd 0f 88 64 01 00 00 e8 b9
RSP: 0018:ffffc9000455f6e0 EFLAGS: 00000217
RAX: ffffffff81e7d801 RBX: 0000000000000000 RCX: ffffffff81e7d8e1
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801b4bfb04
RBP: 0000000000000000 R08: ffff88801b4bfb07 R09: 1ffff11003697f60
R10: dffffc0000000000 R11: ffffed1003697f61 R12: ffff88801b4bfb00
R13: 0000000000000004 R14: ffff88801b4bfac0 R15: 1ffffffff2de0b30
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 zap_pte_range mm/memory.c:1429 [inline]
 zap_pmd_range mm/memory.c:1571 [inline]
 zap_pud_range mm/memory.c:1600 [inline]
 zap_p4d_range mm/memory.c:1621 [inline]
 unmap_page_range+0x1ad1/0x2fe0 mm/memory.c:1642
 unmap_vmas+0x25e/0x3a0 mm/memory.c:1732
 exit_mmap+0x200/0xb50 mm/mmap.c:3302
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbada78f749
Code: Unable to access opcode bytes at 0x7fbada78f71f.
RSP: 002b:00007ffdac243558 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbada78f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00000006ac24364f R09: 00007fbada9b4280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbada9b4280 R14: 0000000000000003 R15: 00007ffdac243610
 </TASK>