rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=085/1/0x4000000000000000 softirq=23048/23048 fqs=647 (detected by 0, t=10502 jiffies, g=26925, q=255) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 144 Comm: kworker/u4:1 Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net RIP: 0010:div64_u64 include/linux/math64.h:69 [inline] RIP: 0010:taprio_set_budget net/sched/sch_taprio.c:555 [inline] RIP: 0010:advance_sched+0x62b/0x940 net/sched/sch_taprio.c:761 Code: 00 e8 29 b1 b3 f9 4c 89 e0 48 c1 e8 03 42 80 3c 30 00 4c 8b 74 24 50 74 08 4c 89 e7 e8 7e af b3 f9 4c 89 e8 31 d2 49 f7 34 24 <49> 89 c4 48 89 df be 04 00 00 00 e8 05 b1 b3 f9 48 89 d8 48 c1 e8 RSP: 0018:ffffc90000dd0c80 EFLAGS: 00000046 RAX: 000000000a000000 RBX: ffff8880247c43a0 RCX: ffffffff88098c77 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880785b5ae0 RBP: ffff8880785b5b40 R08: dffffc0000000000 R09: ffffed100f0b6b5d R10: ffffed100f0b6b5d R11: 1ffff1100f0b6b5c R12: ffff8880785b5ae0 R13: 0000000fa0000000 R14: ffff8880785b5800 R15: 18619ab778000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007e0e1000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __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:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc9000170f900 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 5feb4b83a8d0ec00 RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59ab80 RBP: ffffc9000170fa20 R08: dffffc0000000000 R09: fffffbfff1ff7419 R10: fffffbfff1ff7419 R11: 1ffffffff1ff7418 R12: ffffffff8c11bfa0 R13: 1ffff920002e1f2c R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] inet_twsk_purge+0x119/0x810 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635 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 9168 jiffies! g26925 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:27808 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: 0 Comm: swapper/0 Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:3932 [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:default_idle+0xb/0x10 arch/x86/kernel/process.c:729 Code: bf 48 89 df e8 06 6f 0a f8 eb b5 e8 df af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 97 f4 52 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6 RAX: f3405066c440b200 RBX: ffffffff8bebc3c0 RCX: f3405066c440b200 RDX: 0000000000000001 RSI: ffffffff8a0b11c0 RDI: ffffffff8a59ab80 RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed101720765a R10: ffffed101720765a R11: 1ffff11017207659 R12: ffffffff8d697ba8 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7878 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x486/0x530 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb