rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=50b/1/0x4000000000000000 softirq=73038/73039 fqs=7 (detected by 1, t=10502 jiffies, g=132553, q=101) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10531 Comm: kworker/u4:10 Not tainted 5.15.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline] RIP: 0010:lock_release+0x14d/0x720 kernel/locking/lockdep.c:5641 Code: 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 69 05 00 00 45 8b 8e f4 09 00 00 45 85 c9 0f 85 9e 02 00 00 9c 8f 04 24 48 c7 c7 80 fc 8b 89 e8 16 ec d9 07 48 89 da 83 e3 07 48 b8 00 RSP: 0018:ffffc90000007d08 EFLAGS: 00000046 RAX: 0000000000000007 RBX: ffffffff8d6e8d4c RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000010002 RDI: ffff88802449c2f4 RBP: 1ffff92000000fa3 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8b97fde0 R13: 178ca6d9af194db3 R14: ffff88802449b900 R15: 178ca6d9af194db3 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3c4657c004 CR3: 000000003b862000 CR4: 0000000000350ef0 Call Trace: rcu_lock_release include/linux/rcupdate.h:272 [inline] rcu_read_unlock include/linux/rcupdate.h:720 [inline] advance_sched+0x507/0x9a0 net/sched/sch_taprio.c:765 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:debug_smp_processor_id+0x0/0x20 lib/smp_processor_id.c:60 Code: 2b e4 89 4d 8d 86 c8 07 00 00 83 e9 01 e8 31 09 be ff 48 8b 74 24 28 48 c7 c7 a0 2b e4 89 e8 20 09 be ff e8 ad d0 cc ff eb a2 <0f> 1f 44 00 00 48 c7 c6 e0 2b e4 89 48 c7 c7 20 2c e4 89 e9 a8 fe RSP: 0018:ffffc900049cfb20 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 000000000007ffff RCX: bf64d0b17fe60e07 RDX: 1ffff1100489385e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000004e0e8 R08: 0000000000000000 R09: ffffffff8fcfc927 R10: fffffbfff1f9f924 R11: 0000000000000000 R12: ffffffff8d3ba600 R13: ffffc900049cfca8 R14: 000000000000000a R15: dffffc0000000000 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:330 [inline] rcu_is_watching+0xe/0xc0 kernel/rcu/tree.c:1121 rcu_read_lock include/linux/rcupdate.h:688 [inline] inet_twsk_purge+0x11c/0x7d0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:591 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10488 jiffies! g132553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted 5.15.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:969 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 10 48 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90001cff9f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9c39ce0 RCX: 0000000000000000 RDX: ffff8880162f8000 RSI: ffffffff816ab5a0 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816ab5c6 R11: 0000000000000000 R12: ffffed101738739d R13: 0000000000000000 R14: ffff8880b9c39ce8 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:929 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:626 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:618 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 02 48 89 add -0x77(%rax),%cl 3: f8 clc 4: 83 e0 07 and $0x7,%eax 7: 83 c0 03 add $0x3,%eax a: 38 d0 cmp %dl,%al c: 7c 08 jl 0x16 e: 84 d2 test %dl,%dl 10: 0f 85 69 05 00 00 jne 0x57f 16: 45 8b 8e f4 09 00 00 mov 0x9f4(%r14),%r9d 1d: 45 85 c9 test %r9d,%r9d 20: 0f 85 9e 02 00 00 jne 0x2c4 26: 9c pushfq 27: 8f 04 24 popq (%rsp) * 2a: fa cli <-- trapping instruction 2b: 48 c7 c7 80 fc 8b 89 mov $0xffffffff898bfc80,%rdi 32: e8 16 ec d9 07 callq 0x7d9ec4d 37: 48 89 da mov %rbx,%rdx 3a: 83 e3 07 and $0x7,%ebx 3d: 48 rex.W 3e: b8 .byte 0xb8