rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (6 ticks this GP) idle=656/1/0x4000000000000000 softirq=135993/135993 fqs=0 (detected by 1, t=10502 jiffies, g=245813, q=3379) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 29119 Comm: syz-executor.2 Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:174 [inline] RIP: 0010:__lock_acquire+0x1332/0x5640 kernel/locking/lockdep.c:4422 Code: 00 48 8d 7d f8 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dc 3f 00 00 0f b7 5d f8 <66> 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 f8 06 48 8d RSP: 0018:ffffc90000006e78 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 000000000000202b RCX: ffffffff815a0dee RDX: 1ffff1100ca21dcd RSI: 0000000053957cee RDI: ffff88806510ee68 RBP: ffff88806510ee70 R08: 0000000000000005 R09: 0000000000000000 R10: fffffbfff18be73c R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88806510e4c0 R15: 0000000000000000 FS: 00007f93ac250700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000054688000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 rcu_lock_acquire include/linux/rcupdate.h:241 [inline] rcu_read_lock include/linux/rcupdate.h:634 [inline] is_bpf_text_address+0x36/0x160 kernel/bpf/core.c:704 kernel_text_address kernel/extable.c:151 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:120 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312 perf_callchain_kernel+0x467/0x6a0 arch/x86/events/core.c:2450 get_perf_callchain+0x16e/0x620 kernel/events/callchain.c:200 perf_callchain+0x165/0x1c0 kernel/events/core.c:6985 perf_prepare_sample+0x8fd/0x1d40 kernel/events/core.c:7012 __perf_event_output kernel/events/core.c:7170 [inline] perf_event_output_forward+0xf3/0x270 kernel/events/core.c:7190 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8845 perf_swevent_overflow kernel/events/core.c:8921 [inline] perf_swevent_event+0x347/0x550 kernel/events/core.c:8949 perf_tp_event+0x2e4/0xb50 kernel/events/core.c:9377 perf_trace_run_bpf_submit+0x11c/0x200 kernel/events/core.c:9351 perf_trace_preemptirq_template+0x289/0x440 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle include/trace/events/preemptirq.h:40 [inline] trace_irq_enable_rcuidle include/trace/events/preemptirq.h:40 [inline] trace_hardirqs_on+0x18a/0x220 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:611 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:rcu_read_unlock_special kernel/rcu/tree_plugin.h:630 [inline] RIP: 0010:__rcu_read_unlock+0x488/0x560 kernel/rcu/tree_plugin.h:395 Code: 48 c7 c0 c8 3b b6 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 53 48 83 3d 47 75 54 08 00 74 13 4c 89 e7 57 9d <0f> 1f 44 00 00 e9 ed fb ff ff 0f 0b 0f 0b 0f 0b 0f 0b 4c 89 ef e8 RSP: 0018:ffffc90000007b40 EFLAGS: 00000286 RAX: 1ffffffff136c779 RBX: ffffffff89bd9901 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000286 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffffff8c5f3a97 R10: fffffbfff18be752 R11: 0000000000000001 R12: 0000000000000286 R13: 0000000000000200 R14: ffff8880ae636c00 R15: 0000000000000000 rcu_read_unlock include/linux/rcupdate.h:687 [inline] mld_sendpack+0x742/0xdb0 net/ipv6/mcast.c:1690 mld_send_initial_cr.part.0+0x106/0x150 net/ipv6/mcast.c:2096 mld_send_initial_cr net/ipv6/mcast.c:1191 [inline] mld_dad_timer_expire+0x1c7/0x6a0 net/ipv6/mcast.c:2115 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 Code: c0 d8 3b b6 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 46 f6 bf 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 db 6d 59 f9 65 8b 05 d4 b8 0b 78 85 c0 74 02 5d RSP: 0018:ffffc90005777978 EFLAGS: 00000286 RAX: 1ffffffff136c77b RBX: ffff88806510e4c0 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff87f6456f RBP: ffff8880ae635e00 R08: 0000000000000001 R09: ffffffff8c5f3abf R10: fffffbfff18be757 R11: 0000000000000001 R12: ffff8880ae635e00 R13: ffff888061fbe0c0 R14: 0000000000000000 R15: 0000000000000001 finish_lock_switch kernel/sched/core.c:3517 [inline] finish_task_switch+0x147/0x750 kernel/sched/core.c:3617 context_switch kernel/sched/core.c:3781 [inline] __schedule+0x8ed/0x21e0 kernel/sched/core.c:4527 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:4683 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:40 smp_call_function_single+0x467/0x4f0 kernel/smp.c:384 task_function_call+0xd7/0x160 kernel/events/core.c:116 perf_install_in_context+0x2cb/0x550 kernel/events/core.c:2895 __do_sys_perf_event_open+0x1c31/0x2cb0 kernel/events/core.c:11992 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f93ac24fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000024780 RCX: 000000000045d5b9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000020000180 RBP: 000000000118cf90 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000118cf4c R13: 00007fff5625dcaf R14: 00007f93ac2509c0 R15: 000000000118cf4c rcu: rcu_preempt kthread starved for 10502 jiffies! g245813 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:29080 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294