rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=12377, q=933 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10494 (4294970644-4294960150), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10494 jiffies! g12377 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:26568 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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: 6026 Comm: syz.3.20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:131 [inline] RIP: 0010:lock_release+0x565/0x8c0 kernel/locking/lockdep.c:5777 Code: 8a e8 5f ca 1b 09 b8 ff ff ff ff 65 0f c1 05 9a e1 99 7e 83 f8 01 75 7f 43 c6 44 2f 04 00 48 c7 84 24 80 00 00 00 00 00 00 00 <9c> 8f 84 24 80 00 00 00 f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 RSP: 0018:ffffc900001f0c40 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: df81ba463f199d00 RDX: 0000000000000000 RSI: ffffffff8acada80 RDI: ffffffff8b1c81e0 RBP: ffffc900001f0d50 R08: ffffffff8e8addaf R09: 1ffffffff1d15bb5 R10: dffffc0000000000 R11: fffffbfff1d15bb6 R12: ffff88802d0264e0 R13: dffffc0000000000 R14: ffff88802d0264d0 R15: 1ffff9200003e194 FS: 0000555577f73500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 0000000030be9000 CR4: 00000000003506e0 Call Trace: seqcount_lockdep_reader_access+0xe4/0x1d0 include/linux/seqlock.h:103 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get+0x7f/0x280 kernel/time/timekeeping.c:848 clockevents_program_event+0xe6/0x310 kernel/time/clockevents.c:326 hrtimer_interrupt+0x5a1/0x9c0 kernel/time/hrtimer.c:1889 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ba 9c da f6 48 89 df e8 72 71 db f6 e8 1d 7d ff f6 fb bf 01 00 00 00 92 78 ce f6 65 8b 05 63 af 75 75 85 c0 74 02 5b c3 e8 e0 96 72 RSP: 0018:ffffc90003657c78 EFLAGS: 00000286 RAX: df81ba463f199d00 RBX: ffff888077fa1bc0 RCX: df81ba463f199d00 RDX: dffffc0000000000 RSI: ffffffff8acac900 RDI: 0000000000000001 RBP: ffff888077fa2058 R08: ffffffff8e8addaf R09: 1ffffffff1d15bb5 R10: dffffc0000000000 R11: fffffbfff1d15bb6 R12: 1ffff1100eff440b R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x11f5/0x13f0 kernel/signal.c:2905 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa979d9bf79 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:00007ffc152d0e78 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fa97a015fa0 RCX: 00007fa979d9bf79 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa979e327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa97a015fac R14: 00007fa97a015fa0 R15: 00007fa97a015fa0