rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=7381, q=34 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294954918-4294944418), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g7381 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:27840 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 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: 4280 Comm: syz-executor387 Not tainted 6.1.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:hrtimer_interrupt+0x6c3/0x8d0 kernel/time/hrtimer.c:1831 Code: ff ff ff 48 8b 0c 24 80 e1 07 38 c1 0f 8c e1 fc ff ff 48 8b 3c 24 e8 0c 61 61 00 e9 d3 fc ff ff e8 82 ed 0f 00 48 8b 44 24 08 <42> 0f b6 04 30 84 c0 0f 85 5a 01 00 00 41 80 65 00 fb e9 c0 00 00 RSP: 0018:ffffc900001e0ea8 EFLAGS: 00000006 RAX: 1ffff110171e54b9 RBX: ffff8880b8f2a580 RCX: ffff888072d41dc0 RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000002974831ff0 R08: dffffc0000000000 R09: fffffbfff1bfd046 R10: fffffbfff1bfd046 R11: 1ffffffff1bfd045 R12: 00000029749b6480 R13: ffff8880b8f2a5cc R14: dffffc0000000000 R15: 0000000000000000 FS: 0000555590e443c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdd4dd7a9e0 CR3: 000000002fd80000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 1b 4a f7 48 89 df e8 a6 e0 4a f7 e8 11 e3 6d f7 fb bf 01 00 00 00 b6 5d 3e f7 65 8b 05 b7 22 e9 75 85 c0 74 02 5b c3 e8 04 34 e7 RSP: 0018:ffffc90003bf7bb8 EFLAGS: 00000286 RAX: 107814d9e7775000 RBX: ffff88802f229bc0 RCX: 107814d9e7775000 RDX: dffffc0000000000 RSI: ffffffff8a6bfe00 RDI: 0000000000000001 RBP: ffff88802f22a058 R08: dffffc0000000000 R09: ffffed1005e45379 R10: ffffed1005e45379 R11: 1ffff11005e45378 R12: 1ffff11005e4540b 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: 0033:0x7fdd4dd61809 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 1d 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 01 48 RSP: 002b:00007fff8b5c1408 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fdd4dd61809 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007fdd4dd19990 R09: 00007fdd4dd19990 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdd4ddb80dc R13: 00007fdd4ddb111f R14: 00007fff8b5c1440 R15: 0000000000000000