rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=503/0/0x1 softirq=6876/6876 fqs=0 (t=10501 jiffies g=6725 q=459) rcu: rcu_preempt kthread starved for 10502 jiffies! g6725 f0x0 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:26960 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 4552 Comm: syz.4.76 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:__this_cpu_preempt_check+0x0/0x10 lib/smp_processor_id.c:65 Code: 48 89 da e8 02 48 f5 ff 48 8b 74 24 30 48 c7 c7 c0 f7 79 8a e8 f1 47 f5 ff e8 1c 09 f8 ff eb a8 e8 d5 ee ff ff 0f 1f 44 00 00 <48> 89 fe 48 c7 c7 40 f7 79 8a e9 e1 fe ff ff 00 eb 1e 0f 1f 00 48 RSP: 0018:ffffc9000122fef0 EFLAGS: 00000046 RAX: ffffffffffffffff RBX: ffff8880219dd940 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8a32e820 RDI: ffffffff8a2b2780 RBP: ffffc9000122ff48 R08: ffffffff8d89db2f R09: 1ffffffff1b13b65 R10: dffffc0000000000 R11: fffffbfff1b13b66 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff89bbe168 R15: 000000000000000f FS: 00007fce953786c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe35849f6b8 CR3: 0000000023543000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_on+0x94/0x140 kernel/locking/lockdep.c:4340 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fce9713d510 Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 4a 27 07 00 e8 e5 65 f9 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48 RSP: 002b:00007fce95377b38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fce97397fa8 RCX: 00007fce9711df79 RDX: 00007fce95377b40 RSI: 00007fce95377c70 RDI: 0000000000000021 RBP: 00007fce97397fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce97398038 R14: 00007fffe135bd00 R15: 00007fffe135bde8 NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4ad/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:730 Code: b7 48 89 df e8 16 c5 f8 f7 eb ad e8 4f af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 77 66 60 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffc90000d67d48 EFLAGS: 000002c2 RAX: faaa96fa2a872e00 RBX: ffff888017960000 RCX: faaa96fa2a872e00 RDX: 0000000000000001 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f740 RBP: ffffc90000d67e80 R08: ffff8880b913b30b R09: 1ffff11017227661 R10: dffffc0000000000 R11: ffffed1017227662 R12: 1ffff11002f2c000 R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff920001acfb4 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21f/0x580 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x330/0x430 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb