rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=5809, q=96 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294956149-4294945646), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g5809 f0x2 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:28096 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4282 Comm: syz-executor166 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_preemption_disabled+0x0/0x110 lib/smp_processor_id.c:13 Code: c7 80 70 bc 8c 4c 89 f6 e8 bd 32 17 fa e9 6e ff ff ff 00 00 cc cc 00 00 cc cc 48 c7 c7 80 fa de 8a 48 c7 c6 c0 fa de 8a eb 00 <55> 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 RSP: 0018:ffffc900001e0f00 EFLAGS: 00000046 RAX: 0000000000000806 RBX: ffff888030263b80 RCX: 84e533f855b6f200 RDX: 0000000000000000 RSI: ffffffff8adefac0 RDI: ffffffff8adefa80 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1c3ee26 R10: fffffbfff1c3ee26 R11: 1ffffffff1c3ee25 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff888030263b80 R15: 1ffff9200003c1e8 FS: 00007f8cc3a616c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8cc3a60e40 CR3: 000000002f864000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: irqtime_account_irq+0x14/0x1b0 kernel/sched/cputime.c:51 account_hardirq_exit include/linux/vtime.h:159 [inline] __irq_exit_rcu+0x8d/0x220 kernel/softirq.c:676 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 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: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 18 42 f7 48 89 df e8 e6 dd 42 f7 e8 61 d1 65 f7 fb bf 01 00 00 00 46 5b 36 f7 65 8b 05 67 14 e1 75 85 c0 74 02 5b c3 e8 b4 25 df RSP: 0018:ffffc90003dd7bb8 EFLAGS: 00000286 RAX: 84e533f855b6f200 RBX: ffff88802e8c1bc0 RCX: 84e533f855b6f200 RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: 0000000000000001 RBP: ffff88802e8c2058 R08: dffffc0000000000 R09: ffffed1005d18379 R10: ffffed1005d18379 R11: 1ffff11005d18378 R12: 1ffff11005d1840b 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+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 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:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8cc3aa0457 Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 RSP: 002b:00007f8cc3a61218 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f8cc3b2a308 RCX: 00007f8cc3aa0459 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8cc3b2a308 RBP: 00007f8cc3b2a300 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000140 R13: 000020000006b000 R14: 0000200000000100 R15: 0000200000000680