rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=39f/1/0x4000000000000000 softirq=15182/15182 fqs=10 (detected by 0, t=10502 jiffies, g=20265, q=282) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1109 Comm: kworker/1:2 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events nsim_dev_trap_report_work RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] RIP: 0010:lock_is_held_type+0x100/0x190 kernel/locking/lockdep.c:5667 Code: ff 74 16 89 e9 31 c0 41 f6 47 22 03 0f 95 c0 31 ed 39 c1 40 0f 94 c5 eb 05 bd 01 00 00 00 48 c7 c7 60 28 0b 8a e8 c0 0d 00 00 ff ff ff ff 65 0f c1 05 13 48 5a 76 83 f8 01 75 40 48 c7 04 24 RSP: 0018:ffffc90000dd0c38 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffff888020e55940 RCX: 11301bcc93a80800 RDX: 0000000000010000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340 RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520001ba180 R11: 1ffff920001ba180 R12: 0000000000000004 R13: 0000000000000046 R14: ffff88805e40a300 R15: ffff888020e564d0 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c249de5 CR3: 000000007b7a6000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:287 [inline] advance_sched+0x141/0x940 net/sched/sch_taprio.c:721 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x53d/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:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:preempt_count_sub+0x2c/0x160 kernel/sched/core.c:5517 Code: 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 60 df 0b 96 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 00 00 00 83 3d 16 6f ba 14 00 75 25 <65> 8b 05 75 ff b0 7e 89 c1 81 e1 ff ff ff 7f 39 cf 7f 25 81 ff ff RSP: 0018:ffffc90004767650 EFLAGS: 00000246 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: ffffffff960bdf03 RDX: ffffc90004767701 RSI: ffffc90004767778 RDI: 0000000000000001 RBP: ffffc900047677d0 R08: dffffc0000000000 R09: ffffc900047677d8 R10: fffff520008ecefd R11: 1ffff920008ecefb R12: ffffc90004760000 R13: dffffc0000000000 R14: ffffc90004767798 R15: ffffc90004767788 unwind_next_frame+0x1296/0x1d90 arch/x86/kernel/unwind_orc.c:616 __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:704 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1162 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x2a1/0xb40 drivers/net/netdevsim/dev.c:762 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10450 jiffies! g20265 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:28128 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: NMI backtrace for cpu 0 CPU: 0 PID: 6353 Comm: syz.9.455 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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: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:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_single+0x212/0x490 kernel/smp.c:758 Code: 48 44 89 f6 83 e6 01 31 ff e8 0a 5c 0b 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 95 58 0b 00 e9 a3 00 00 00 f3 90 44 24 48 01 00 00 00 0f 84 8e 00 00 00 e8 7b 58 0b 00 eb e9 e8 RSP: 0018:ffffc900015bf900 EFLAGS: 00000246 RAX: ffffffff816c6ba5 RBX: 0000000000000000 RCX: 0000000000080000 RDX: ffffc9000fe21000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc900015bf9f0 R08: dffffc0000000000 R09: ffffed1017227679 R10: ffffed1017227679 R11: 1ffff11017227678 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff920002b7f24 loaded_vmcs_clear arch/x86/kvm/vmx/vmx.c:723 [inline] vmx_vcpu_load_vmcs+0x12a/0x780 arch/x86/kvm/vmx/vmx.c:1315 vmx_vcpu_load+0x1a/0x80 arch/x86/kvm/vmx/vmx.c:1380 kvm_arch_vcpu_load+0x190/0x770 arch/x86/kvm/x86.c:4385 vcpu_load+0x4e/0x80 virt/kvm/kvm_main.c:209 kvm_arch_vcpu_ioctl_run+0x53/0x1f40 arch/x86/kvm/x86.c:10337 kvm_vcpu_ioctl+0x887/0xb80 virt/kvm/kvm_main.c:3894 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 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: 0033:0x7f5a9b788be9 Code: 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 01 48 RSP: 002b:00007f5a999ae038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5a9b9b0180 RCX: 00007f5a9b788be9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f5a9b80be19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5a9b9b0218 R14: 00007f5a9b9b0180 R15: 00007fff8531b8b8