rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=4bb/1/0x4000000000000000 softirq=9962/9963 fqs=5 (detected by 0, t=10502 jiffies, g=12013, q=1340) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5225 Comm: udevd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline] RIP: 0010:lock_acquire+0x14b/0x400 kernel/locking/lockdep.c:5619 Code: 0f 85 08 02 00 00 41 83 3e 00 0f 85 16 01 00 00 43 c6 44 3d 08 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 <4c> 8b b4 24 a0 00 00 00 43 c6 44 3d 08 f8 fa 48 c7 c7 e0 39 2b 8a RSP: 0000:ffffc90000dd0ba0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 8fba88985aa55700 RDX: 0000000000000000 RSI: ffffffff8a7a41e0 RDI: ffffffff8a7a41a0 RBP: ffffc90000dd0cb0 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd R10: dffffc0000000000 R11: fffffbfff1b161be R12: ffffffff8c31ef60 R13: 1ffff920001ba180 R14: ffff8880242028ac R15: dffffc0000000000 FS: 00007f89c54c3880(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ea2d074a0 CR3: 00000000242d9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] advance_sched+0x6b2/0x920 net/sched/sch_taprio.c:749 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4ea/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 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:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5671 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0000:ffffc90002e8fd18 EFLAGS: 00000206 RAX: 8fba88985aa55700 RBX: ffff888024201dc0 RCX: 8fba88985aa55700 RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4200 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff203dc1e R10: dffffc0000000000 R11: fffffbfff203dc1f R12: 0000000000000001 R13: 0000000000000246 R14: ffffffff8c31f020 R15: ffff8880242028d8 lock_is_held include/linux/lockdep.h:287 [inline] ___might_sleep+0xea/0x610 kernel/sched/core.c:9624 do_user_addr_fault+0x2f0/0xc90 arch/x86/mm/fault.c:1313 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x563ea2d074a0 Code: Unable to access opcode bytes at RIP 0x563ea2d07476. RSP: 002b:00007ffd5a081d88 EFLAGS: 00010206 RAX: 0000563ec009c3d0 RBX: 0000563ec009c3d0 RCX: 0000000000000010 RDX: 0000563ec00a7e6d RSI: 0000000000000000 RDI: 0000563ec00a64d0 RBP: 0000563ec0083910 R08: 000000000000000e R09: 0000000000000010 R10: 0000563ea2d245e0 R11: 0000000000000004 R12: 00007ffd5a081d90 R13: 00007ffd5a081e40 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10475 jiffies! g12013 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:27440 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 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/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145 kthread+0x42e/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: 4277 Comm: kworker/0:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events bpf_prog_free_deferred 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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x1110/0x1270 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+0x845/0x1120 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+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 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:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0xba3/0xd80 kernel/smp.c:969 Code: 0f b6 44 05 00 84 c0 0f 85 9a 00 00 00 41 8b 1e 89 de 83 e6 01 31 ff e8 fb 73 0b 00 83 e3 01 75 07 e8 91 70 0b 00 eb 42 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 10 41 f7 RSP: 0018:ffffc9000306f860 EFLAGS: 00000293 RAX: ffffffff816d8c45 RBX: 0000000000000001 RCX: ffff88807e6d3b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000306f9a0 R08: ffffffff901ee0cf R09: 1ffffffff203dc19 R10: dffffc0000000000 R11: fffffbfff203dc1a R12: ffff8880b903b3c0 R13: 1ffff110172280b9 R14: ffff8880b91405c8 R15: 0000000000000001 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1134 __purge_vmap_area_lazy+0x21e/0x1940 mm/vmalloc.c:1690 _vm_unmap_aliases+0x40b/0x4a0 mm/vmalloc.c:2114 vm_remove_mappings mm/vmalloc.c:2591 [inline] __vunmap+0x72f/0xa80 mm/vmalloc.c:2618 bpf_jit_binary_free kernel/bpf/core.c:918 [inline] bpf_jit_free+0x92/0x180 kernel/bpf/core.c:931 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287