rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=9e2c/1/0x4000000000000000 softirq=115864/115865 fqs=1
rcu: 	(detected by 1, t=10505 jiffies, g=91033, q=521 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18879 Comm: syz.4.3490 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:-1 [inline]
RIP: 0010:rcu_is_watching+0x1c/0xb0 kernel/rcu/tree.c:751
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 10 1d 1d 11 e8 db 87 de 09 89 c3 83 f8 08 73 65 <49> bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 ad dc 8d 4c 89 f0 48
RSP: 0018:ffffc90000007c50 EFLAGS: 00000093
RAX: 0000000000000000 RBX: 0000000000000000 RCX: f60402dbc7fe0800
RDX: ffff88802c455ac0 RSI: ffffffff8c03aa40 RDI: ffffffff8c03aa00
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff89a340f8
R10: dffffc0000000000 R11: ffffed100ad8665e R12: ffff888056c33360
R13: ffff888056c33000 R14: 1bcbc6f7e6f1bc3d R15: ffff888042db9800
FS:  00007f732e9a56c0(0000) GS:ffff8881259e7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000003d9030 CR3: 00000000784ec000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000009292 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock include/linux/rcupdate.h:842 [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:syscall_enter_from_user_mode_work include/linux/entry-common.h:94 [inline]
RIP: 0010:syscall_enter_from_user_mode include/linux/entry-common.h:125 [inline]
RIP: 0010:do_syscall_64+0xc3/0xfa0 arch/x86/entry/syscall_64.c:90
Code: 00 48 8b 7d 08 48 89 7b 18 e8 b9 72 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 49 12 43 f6 90 90 e8 f2 11 43 f6 fb 49 8b 57 08 <f6> c2 3f 74 0e 4c 89 f7 4c 89 ee e8 cd ed 25 f6 49 89 c4 90 90 41
RSP: 0018:ffffc9000b70fee0 EFLAGS: 00000282
RAX: f60402dbc7fe0800 RBX: ffffc9000b70fee0 RCX: f60402dbc7fe0800
RDX: 0000000000000000 RSI: ffffffff8dba2d53 RDI: ffffffff8c03aa60
RBP: ffffc9000b70ff38 R08: ffffffff8fc39677 R09: 1ffffffff1f872ce
R10: dffffc0000000000 R11: fffffbfff1f872cf R12: 00000000000000ca
R13: 00000000000000ca R14: ffffc9000b70ff48 R15: ffff88802c455ac0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f732db8ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f732e9a50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f732ddd5fa8 RCX: 00007f732db8ec29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f732ddd5fac
RBP: 00007f732ddd5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f732ddd6038 R14: 00007ffd0f8257d0 R15: 00007ffd0f8258b8
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g91033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:26464 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5360 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
 __schedule_loop kernel/sched/core.c:7046 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7061
 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: 1 UID: 0 PID: 18850 Comm: syz.6.3483 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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 36 79 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 e1 74 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 c5 74
RSP: 0018:ffffc9000b427340 EFLAGS: 00000293
RAX: ffffffff81b4645b RBX: 1ffff110170c8441 RCX: ffff888027a6bc80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000b4274c0 R08: ffffffff8fc39677 R09: 1ffffffff1f872ce
R10: dffffc0000000000 R11: fffffbfff1f872cf R12: ffff8880b8642208
R13: dffffc0000000000 R14: ffff8880b873b200 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125ae7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 000000000e138000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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:1361 [inline]
 flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
 exit_mmap+0x174/0xb40 mm/mmap.c:1266
 __mmput+0x118/0x430 kernel/fork.c:1148
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:954
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0dc598ec29
Code: Unable to access opcode bytes at 0x7f0dc598ebff.
RSP: 002b:00007f0dc3bd5038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f0dc5bd6090 RCX: 00007f0dc598ec29
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f0dc5a11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0dc5bd6128 R14: 00007f0dc5bd6090 R15: 00007ffcb2cac358
 </TASK>