rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=5673, q=124) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294954616-4294944113), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g5673 f0x2 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:28064 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 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: NMI backtrace for cpu 0 CPU: 0 PID: 4367 Comm: syz.1.12 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 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+0x4fe/0xc40 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:__rcu_read_unlock+0x2/0xd0 kernel/rcu/tree_plugin.h:415 Code: 11 ff 03 8b 03 3d 00 00 00 40 7d 02 5b c3 0f 0b eb fa 89 d9 80 e1 07 80 c1 03 38 c1 7c e3 48 89 df e8 12 d8 57 00 eb d9 41 57 <41> 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 15 RSP: 0018:ffffc9000300fed0 EFLAGS: 00000246 RAX: ffffffff814ec8a1 RBX: 000000000000000f RCX: 0000000000080000 RDX: ffffc90005939000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff5419 R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: dffffc0000000000 R13: ffff88802aca6140 R14: 0000000000000010 R15: ffff88802aca6228 rcu_read_unlock include/linux/rcupdate.h:772 [inline] __task_pid_nr_ns+0x34e/0x420 kernel/pid.c:501 task_tgid_vnr include/linux/sched.h:1585 [inline] __ia32_sys_getpid+0x19/0x20 kernel/sys.c:945 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc5733865e7 Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d b2 62 d9 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 23 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00 RSP: 002b:00007fc5715f5b08 EFLAGS: 00000202 ORIG_RAX: 0000000000000027 RAX: ffffffffffffffda RBX: 00007fc5715f5c70 RCX: 00007fc5733865e7 RDX: 00007fc5715f5b40 RSI: 00007fc5715f5c70 RDI: 0000000000000021 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fc5735e6038 R14: 00007ffded07a6d0 R15: 00007ffded07a7b8