rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=cd3/1/0x4000000000000000 softirq=9002/9003 fqs=25 (t=10500 jiffies g=11677 q=188) rcu: rcu_preempt kthread timer wakeup didn't happen for 10440 jiffies! g11677 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=3951 rcu: rcu_preempt kthread starved for 10441 jiffies! g11677 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27464 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:722 NMI backtrace for cpu 0 CPU: 0 PID: 4565 Comm: syz.6.25 Not tainted 5.15.181-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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_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:3932 [inline] rcu_sched_clock_irq+0x6d8/0x1110 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:1690 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 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:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:___might_sleep+0x171/0x600 kernel/sched/core.c:9607 Code: ee 49 c1 ee 03 43 0f b6 04 26 84 c0 0f 85 34 03 00 00 45 03 7d 00 44 3b 7c 24 2c 75 61 48 c7 84 24 a0 00 00 00 00 00 00 00 9c <8f> 84 24 a0 00 00 00 f6 84 24 a1 00 00 00 02 74 43 4c 8d 7a 2c 4c RSP: 0018:ffffc90002edf9d8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff920005dbf44 RCX: 98b05bac0cf77600 RDX: ffff8880208f1dc0 RSI: ffffffff8a0b2260 RDI: ffffffff8a59a2c0 RBP: ffffc90002edfb00 R08: dffffc0000000000 R09: ffffc90002edfc50 R10: fffff520005dbf90 R11: 1ffff920005dbf8a R12: dffffc0000000000 R13: ffff8880208f21fc R14: 1ffff1100411e43f R15: 0000000000000000 __might_fault+0x6b/0x110 mm/memory.c:5354 __copy_from_user include/linux/uaccess.h:109 [inline] check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:33 [inline] __fpu_restore_sig arch/x86/kernel/fpu/signal.c:317 [inline] fpu__restore_sig+0x203/0xf50 arch/x86/kernel/fpu/signal.c:466 restore_sigcontext arch/x86/kernel/signal.c:139 [inline] __ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:674 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: 0033:0x7f82f2712967 Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 RSP: 002b:00007f82f01150e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f82f293a248 RCX: 00007f82f2712969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f82f293a248 RBP: 00007f82f293a240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f82f293a24c R13: 0000000000000000 R14: 00007ffe15efeea0 R15: 00007ffe15efef88