rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=16845, q=74 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10499 (4294966805-4294956306), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g16845 f0x2 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:27760 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 4543 Comm: syz.3.20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__next_base kernel/time/hrtimer.c:524 [inline] RIP: 0010:__hrtimer_run_queues+0x166/0xd50 kernel/time/hrtimer.c:1785 Code: 00 00 00 89 de e8 ba 14 10 00 83 fb 20 0f 83 47 0b 00 00 41 0f b3 df 41 89 dc 41 83 e4 1f bf 09 00 00 00 89 de e8 9a 14 10 00 <83> fb 09 0f 83 64 0b 00 00 e8 2c 11 10 00 49 c1 e4 07 4c 03 64 24 RSP: 0018:ffffc90000007d40 EFLAGS: 00000006 RAX: ffffffff81727576 RBX: 0000000000000000 RCX: 0000000000010000 RDX: ffff88805c9e8000 RSI: 0000000000000000 RDI: 0000000000000009 RBP: ffffc90000007e88 R08: ffffffff8e1ffbef R09: 1ffffffff1c3ff7d R10: dffffc0000000000 R11: fffffbfff1c3ff7e R12: 0000000000000000 R13: dffffc0000000000 R14: 1ffff92000000fc0 R15: 0000000000000000 FS: 0000555569f7e500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 000000005a5b7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 5e b1 2c f7 48 89 df e8 a6 79 2d f7 e8 81 d0 50 f7 fb bf 01 00 00 00 f6 dd 20 f7 65 8b 05 f7 4f ca 75 85 c0 74 02 5b c3 e8 44 64 c8 RSP: 0018:ffffc900035d7b98 EFLAGS: 00000282 RAX: 1289dc2092e2f300 RBX: ffff88807c37e5c0 RCX: 1289dc2092e2f300 RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: 0000000000000001 RBP: ffff88807c37ea58 R08: ffff88807c37e5c3 R09: 1ffff1100f86fcb8 R10: dffffc0000000000 R11: ffffed100f86fcb9 R12: 1ffff1100f86fd4b R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1163/0x1350 kernel/signal.c:2874 arch_do_signal_or_restart+0xc4/0x1350 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:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2ec2d9ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffced8a97a8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f2ec3015fa0 RCX: 00007f2ec2d9ce59 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f2ec2e32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2ec3015fac R14: 00007f2ec3015fa0 R15: 00007f2ec3015fa0