rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=49cc/1/0x4000000000000000 softirq=73130/73131 fqs=0
rcu: (detected by 0, t=10502 jiffies, g=62809, q=133 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13809 Comm: syz.1.1733 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:_raw_spin_lock_irq+0x5/0xf0 kernel/locking/spinlock.c:169
Code: 5c 41 5e 41 5f 5d e9 da 4f 00 00 cc e8 14 6c fd ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 53 48 83 e4 e0 48 83 ec 60 48 89 fb 65 48 8b
RSP: 0018:ffffc90000a08d30 EFLAGS: 00000006
RAX: ffffffff81ae4fde RBX: ffff8880b8727c08 RCX: ffff8880263d8000
RDX: 0000000000010000 RSI: ffffffff8c03da40 RDI: ffff8880b8727ac0
RBP: ffffc90000a08e90 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee
R10: dffffc0000000000 R11: fffffbfff1f86aef R12: ffff88807b848340
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8727bc0
FS: 000055555ee67500(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000002d9f0000 CR4: 00000000003526f0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:1781 [inline]
__hrtimer_run_queues+0x602/0xc60 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
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5193
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 7f 81 f0 09 e8 6a 5d 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 58 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900041ef7d8 EFLAGS: 00000286
RAX: cfb06b408498e900 RBX: 0000000000000000 RCX: cfb06b408498e900
RDX: 0000000000000000 RSI: ffffffff8db9fb03 RDI: ffffffff8c03da60
RBP: ffffc900041ef830 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee
R10: dffffc0000000000 R11: fffffbfff1f86aef R12: ffff8880263d8000
R13: dffffc0000000000 R14: ffff88805ee2bc80 R15: ffff8880b873ab98
context_switch kernel/sched/core.c:5328 [inline]
__schedule+0x17a0/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_futex_key+0x0/0x1660 kernel/futex/core.c:550
Code: 41 5e 41 5f 5d c3 cc cc cc cc cc 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0018:ffffc900041efbd8 EFLAGS: 00000246
RAX: ffffffff81b47723 RBX: ffffc900041efc40 RCX: 0000000000000000
RDX: ffffc900041efc40 RSI: 0000000000000002 RDI: 00007f90af3e6188
RBP: ffffc900041efcf0 R08: ffffc900041efc57 R09: 0000000000000000
R10: ffffc900041efc40 R11: fffff5200083df8b R12: 0000000000000002
R13: 00007f90af3e6188 R14: dffffc0000000000 R15: 00000000ffffffff
futex_wake+0xf8/0x560 kernel/futex/waitwake.c:165
do_futex+0x395/0x420 kernel/futex/syscalls.c:135
__do_sys_futex kernel/futex/syscalls.c:207 [inline]
__se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
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: 0033:0x7f90af18eec9
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:00007ffcfc16b848 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f90af3e6188 RCX: 00007f90af18eec9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f90af3e6188
RBP: 0000000000000002 R08: 0000000000000016 R09: 00000014fc16bb3f
R10: 00007f90af3e5fa0 R11: 0000000000000246 R12: 00007f90af3e618c
R13: 00007f90af3e6180 R14: 0000000000001c0b R15: 0000000000000002
rcu: rcu_preempt kthread starved for 10502 jiffies! g62809 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:26696 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 13831 Comm: syz.2.1738 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+0xd3c/0x12d0 kernel/smp.c:877
Code: 01 31 ff e8 96 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 41 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 25 6f 0b 00 eb e4 44 89 e1 80 e1
RSP: 0018:ffffc900058c7340 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff110170e7ffd RCX: ffff888066d6dac0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900058c74c0 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee
R10: dffffc0000000000 R11: fffffbfff1f86aef R12: ffff8880b873ffe8
R13: dffffc0000000000 R14: ffff8880b863b200 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881259fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f01327b3f98 CR3: 000000000e138000 CR4: 00000000003526f0
Call Trace:
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:1133
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: 0033:0x7f2ebed8eec9
Code: Unable to access opcode bytes at 0x7f2ebed8ee9f.
RSP: 002b:00007f2ebfbba0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f2ebefe6188 RCX: 00007f2ebed8eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2ebefe6188
RBP: 00007f2ebefe6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2ebefe6218 R14: 00007fff80f91cc0 R15: 00007fff80f91da8