rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=d12c/1/0x4000000000000000 softirq=23472/23480 fqs=62
rcu: 	(detected by 0, t=10504 jiffies, g=16413, q=1571 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6662 Comm: cmp Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:debug_smp_processor_id+0xb/0x20 lib/smp_processor_id.c:58
Code: 7b f9 e9 66 ff ff ff cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 c7 c7 00 09 bf 8b <48> c7 c6 40 09 bf 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90
RSP: 0018:ffffc90000a08c48 EFLAGS: 00000002
RAX: ffffffff89604e58 RBX: ffffffff89604e28 RCX: 0000000000010000
RDX: ffff8880264f8000 RSI: 0000000000000001 RDI: ffffffff8bbf0900
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff89604e28
R10: dffffc0000000000 R11: ffffed100930e25e R12: ffff888049871360
R13: ffff888049871000 R14: 187c4dee70c5f8ff R15: ffff88805b951000
FS:  0000000000000000(0000) GS:ffff888126238000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6375cd3e9c CR3: 000000000dd38000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
 rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751
 rcu_read_lock include/linux/rcupdate.h:868 [inline]
 advance_sched+0xa31/0xc90 net/sched/sch_taprio.c:990
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
RIP: 0010:_raw_spin_lock_irqsave+0x60/0xf0 kernel/locking/spinlock.c:162
Code: 78 8d 48 c7 44 24 10 e0 43 49 8b 49 89 e7 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 49 bc 00 00 00 00 00 fc ff df 4b 89 04 27 <48> c7 44 24 20 00 00 00 00 9c 8f 44 24 20 4c 8b 74 24 20 fa 41 f7
RSP: 0018:ffffc90002f579a0 EFLAGS: 00000a02
RAX: f3f3f300f1f1f1f1 RBX: ffffffff99a9bd08 RCX: 000000000001f5e0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff99a9bd08
RBP: ffffc90002f57a30 R08: ffffc90002f57a67 R09: 0000000000000000
R10: ffffc90002f57a58 R11: fffff520005eaf4d R12: dffffc0000000000
R13: 1ffff920005eaf68 R14: dffffc0000000000 R15: 1ffff920005eaf34
 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
 __call_rcu_common kernel/rcu/tree.c:3108 [inline]
 call_rcu+0xaa/0x9c0 kernel/rcu/tree.c:3243
 slab_free_hook mm/slub.c:2507 [inline]
 slab_free mm/slub.c:6642 [inline]
 kmem_cache_free+0x4b5/0x690 mm/slub.c:6752
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6b5/0x2300 kernel/exit.c:966
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
 __do_sys_exit_group kernel/exit.c:1118 [inline]
 __se_sys_exit_group kernel/exit.c:1116 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6375e326c5
Code: Unable to access opcode bytes at 0x7f6375e3269b.
RSP: 002b:00007ffd5f815c68 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f6375f33fe8 RCX: 00007f6375e326c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007ffd5f815bf8 R09: 0000000000000000
R10: 00007ffd5f815a90 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6375f32680 R15: 00007f6375f34000
 </TASK>
rcu: rcu_preempt kthread starved for 10194 jiffies! g16413 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:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6393 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 91 6f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 75 6f
RSP: 0000:ffffc90003017700 EFLAGS: 00000293
RAX: ffffffff81b4943b RBX: 1ffff11017127ffd RCX: ffff888026398000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003017880 R08: ffffffff8f7cf777 R09: 1ffffffff1ef9eee
R10: dffffc0000000000 R11: fffffbfff1ef9eef R12: ffff8880b893ffe8
R13: dffffc0000000000 R14: ffff8880b883b240 R15: 0000000000000001
FS:  00007fe4a5a3d880(0000) GS:ffff888126138000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005569f2510f28 CR3: 0000000077d7c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline]
 flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1471
 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101
 wp_page_copy mm/memory.c:3746 [inline]
 do_wp_page+0x1bc2/0x5800 mm/memory.c:4141
 handle_pte_fault mm/memory.c:6211 [inline]
 __handle_mm_fault+0x1033/0x5400 mm/memory.c:6336
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6505
 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fe4a52b5b69
Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd1d844f10 EFLAGS: 00010202
RAX: 00007fe4a53f2260 RBX: 00000000000078f0 RCX: 00005569f2510f00
RDX: 00005569f2510f00 RSI: 00007fe4a53f2260 RDI: 00005569f2510f00
RBP: 00007fe4a53f1ac0 R08: 00000000000078f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005569f250d770
R13: 00007fe4a53f1ac0 R14: 00000000000078f0 R15: 00007fe4a53f1ac0
 </TASK>