rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=fe1c/1/0x4000000000000000 softirq=54036/54041 fqs=0 rcu: (t=10500 jiffies g=45297 q=273 ncpus=2) rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g45297 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=42948 rcu: rcu_preempt kthread starved for 10500 jiffies! g45297 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 CPU: 0 UID: 0 PID: 61 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd31/0x12d0 kernel/smp.c:877 Code: 00 00 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 0b 00 eb 38 90 42 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 RSP: 0018:ffffc9000212f660 EFLAGS: 00000293 RAX: ffffffff81b44ceb RBX: 1ffff110170e7f61 RCX: ffff88801cb48000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000212f7e0 R08: ffffffff8fa38337 R09: 1ffffffff1f47066 R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffff8880b873fb08 R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c29e8ea CR3: 000000000df36000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10230 Comm: kworker/u8:19 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:trace_hrtimer_cancel include/trace/events/timer.h:317 [inline] RIP: 0010:debug_deactivate+0x82/0x200 kernel/time/hrtimer.c:491 Code: 24 31 75 00 31 f6 4c 0f a3 35 5a 9d f5 0d 0f 92 c3 40 0f 92 c6 bf 02 00 00 00 e8 49 c8 11 00 84 db 74 10 e8 30 77 f8 ff 84 c0 <74> 0e e8 37 c5 11 00 eb 15 e8 30 c5 11 00 eb 0e 80 3d c2 83 df 0d RSP: 0018:ffffc90000a08d18 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000001 RCX: a0e7ca0332ae5800 RDX: ffff8880267bbc00 RSI: ffffffff8be33660 RDI: ffffffff8be33620 RBP: ffffc90000a08e90 R08: ffffffff8fa38337 R09: 1ffffffff1f47066 R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffff88805359a340 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8727c80 FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa2c1ce56c0 CR3: 0000000059158000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1729 [inline] __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:crng_make_state+0x406/0x700 drivers/char/random.c:394 Code: 9b 8e e8 2d b2 29 06 e9 56 fe ff ff e8 43 50 6d fc e8 2e 1d 27 06 4d 85 f6 74 8c e8 34 50 6d fc fb 48 c7 44 24 40 0e 36 e0 45 <48> 8b 44 24 38 4a c7 04 20 00 00 00 00 66 42 c7 44 20 09 00 00 42 RSP: 0018:ffffc9000b4b7740 EFLAGS: 00000293 RAX: ffffffff85525afc RBX: 0000000000000000 RCX: ffff8880267bbc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000b4b7830 R08: ffffffff8fa38337 R09: 1ffffffff1f47066 R10: dffffc0000000000 R11: fffffbfff1f47067 R12: dffffc0000000000 R13: ffff8880b8736310 R14: 0000000000000200 R15: ffff8880b8736360 _get_random_bytes+0xd5/0x210 drivers/char/random.c:406 eth_random_addr include/linux/etherdevice.h:238 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:771 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x38d/0xb80 drivers/net/netdevsim/dev.c:866 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245