rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=9041, q=52 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4294957659-4294947158), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g9041 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:27528 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 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: 5819 Comm: syz-executor784 Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:lock_release+0x1f/0x8b0 kernel/locking/lockdep.c:5762 Code: ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 49 89 f4 <48> 89 7c 24 18 65 48 8b 04 25 28 00 00 00 48 89 84 24 c0 00 00 00 RSP: 0018:ffffc900001f0c40 EFLAGS: 00000082 RAX: 5387cfc5e641e300 RBX: ffffffff8176069f RCX: 5387cfc5e641e300 RDX: 0000000000000000 RSI: ffffffff8176069f RDI: ffffffff8cd49bc8 RBP: ffffc900001f0d50 R08: dffffc0000000000 R09: 1ffffffff21b46a5 R10: dffffc0000000000 R11: fffffbfff21b46a6 R12: ffffffff8176069f R13: 0000002ff1c9d800 R14: 1ffff9200003e1ac R15: dffffc0000000000 FS: 000055558e4083c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 000000007dd63000 CR4: 00000000003506e0 Call Trace: seqcount_lockdep_reader_access+0xdd/0x1c0 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:1894 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 9a c8 f0 f6 48 89 df e8 b2 9a f1 f6 e8 4d 37 15 f7 fb bf 01 00 00 00 92 b2 e4 f6 65 8b 05 93 f8 8c 75 85 c0 74 02 5b c3 e8 70 da 89 RSP: 0018:ffffc9000477fc98 EFLAGS: 00000282 RAX: 5387cfc5e641e300 RBX: ffff88802e8b9bc0 RCX: 5387cfc5e641e300 RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: 0000000000000001 RBP: ffff88802e8ba058 R08: ffffffff8e4a84ef R09: 1ffffffff1c9509d R10: dffffc0000000000 R11: fffffbfff1c9509e R12: 1ffff11005d1740b R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x11f5/0x1400 kernel/signal.c:2905 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f69f7523899 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 19 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:00007fff2cc72868 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f69f7523899 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007f69f74e3990 R09: 00007f69f74e3990 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f69f758133c R13: 00007f69f757b106 R14: 00007fff2cc728a0 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.008 msecs