rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (315 ticks this GP) idle=d5a/1/0x4000000000000000 softirq=19448/19448 fqs=148 (t=10501 jiffies g=22229 q=231) rcu: rcu_preempt kthread starved for 5216 jiffies! g22229 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:28888 pid: 13 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x148/0x250 kernel/time/timer.c:1878 rcu_gp_fqs_loop kernel/rcu/tree.c:1940 [inline] rcu_gp_kthread+0xbbe/0x1d70 kernel/rcu/tree.c:2113 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 NMI backtrace for cpu 1 CPU: 1 PID: 11954 Comm: syz-executor.2 Not tainted 5.11.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x1f4/0x230 kernel/rcu/tree_stall.h:337 print_cpu_stall kernel/rcu/tree_stall.h:569 [inline] check_cpu_stall kernel/rcu/tree_stall.h:643 [inline] rcu_pending kernel/rcu/tree.c:3751 [inline] rcu_sched_clock_irq.cold+0x48e/0xedf kernel/rcu/tree.c:2580 update_process_times+0x16d/0x200 kernel/time/timer.c:1782 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline] sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0010:__local_bh_disable_ip+0x7/0xb0 kernel/softirq.c:121 Code: 48 8b 44 24 78 65 48 2b 04 25 28 00 00 00 75 07 48 83 ec 80 5b 5d c3 e8 d7 3e b5 07 0f 1f 80 00 00 00 00 65 8b 05 49 8d bd 7e 00 00 0f 00 55 53 89 f3 0f 85 82 00 00 00 9c 5d fa 65 01 1d 30 RSP: 0018:ffffc90000db0c18 EFLAGS: 00000246 RAX: 0000000000000101 RBX: 0000000000000001 RCX: 0000000000000100 RDX: ffff8880168ad340 RSI: 0000000000000201 RDI: ffffffff87aaf3c8 RBP: ffff888024727988 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87aaf6ad R11: 0000000000000000 R12: 0000000000000001 R13: ffff888024727b5c R14: ffff888024727800 R15: 0000000000000040 __raw_read_lock_bh include/linux/rwlock_api_smp.h:175 [inline] _raw_read_lock_bh+0x13/0x70 kernel/locking/spinlock.c:247 ipv6_get_lladdr+0x108/0x480 net/ipv6/addrconf.c:1859 addrconf_rs_timer+0x3bc/0x820 net/ipv6/addrconf.c:3874 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x2bc/0xa29 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0010:__tlb_remove_page_size+0xbf/0x420 mm/mmu_gather.c:81 Code: 02 00 00 48 b8 00 00 00 00 00 fc ff df 44 8b 65 08 4a 8d 7c e5 10 45 8d 6c 24 01 48 89 fa 48 c1 ea 03 44 89 6d 08 80 3c 02 00 <0f> 85 e1 02 00 00 48 8d 7d 0c 4e 89 74 e5 10 48 b8 00 00 00 00 00 RSP: 0018:ffffc90009d6f760 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc90009d6fa60 RCX: 0000000000000000 RDX: 1ffff110052988b6 RSI: ffffffff81a87520 RDI: ffff8880294c45b0 RBP: ffff8880294c4000 R08: 0000000000000000 R09: ffffea000187e433 R10: ffffffff81a87512 R11: 0000000000000000 R12: 00000000000000b4 R13: 00000000000000b5 R14: ffffea000187e400 R15: ffffc90009d6fa88 __tlb_remove_page include/asm-generic/tlb.h:438 [inline] zap_pte_range mm/memory.c:1267 [inline] zap_pmd_range mm/memory.c:1368 [inline] zap_pud_range mm/memory.c:1397 [inline] zap_p4d_range mm/memory.c:1418 [inline] unmap_page_range+0xea7/0x2640 mm/memory.c:1439 unmap_single_vma+0x198/0x300 mm/memory.c:1484 unmap_vmas+0x168/0x2e0 mm/memory.c:1516 exit_mmap+0x2b1/0x5a0 mm/mmap.c:3220 __mmput+0x122/0x470 kernel/fork.c:1082 mmput+0x53/0x60 kernel/fork.c:1103 exit_mm kernel/exit.c:501 [inline] do_exit+0xb6a/0x2ae0 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x427/0x20f0 kernel/signal.c:2773 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: Unable to access opcode bytes at RIP 0x45e1ef. RSP: 002b:00007f9b67e5ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000119bf88 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000119bf88 RBP: 000000000119bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffd91887a2f R14: 00007f9b67e5d9c0 R15: 000000000119bf8c