rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (2289 ticks this GP) idle=e26/1/0x4000000000000000 softirq=113823/113823 fqs=19 (t=10501 jiffies g=231417 q=34902) rcu: rcu_preempt kthread starved for 10452 jiffies! g231417 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:29624 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xea9/0x2230 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 NMI backtrace for cpu 0 CPU: 0 PID: 16417 Comm: syz-executor.0 Not tainted 5.9.0-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:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x60 kernel/kcov.c:197 Code: 5d be 03 00 00 00 e9 66 27 27 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 48 8b 14 25 c0 fe 01 00 <65> 8b 05 f0 b0 8d 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc90000006d90 EFLAGS: 00000216 RAX: 0000000000000000 RBX: ffff888036ade200 RCX: ffffffff86f031d9 RDX: ffff88803090e040 RSI: ffff88803090e040 RDI: 0000000000000005 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000002 R10: 000000000000003f R11: 0000000000000001 R12: ffff8880968a3c40 R13: 0000000000000080 R14: ffffc90000006e30 R15: 0000000000000000 ipv6_prefix_equal include/net/ipv6.h:606 [inline] fib6_node_lookup_1+0x2f8/0x8f0 net/ipv6/ip6_fib.c:1586 fib6_node_lookup+0xbe/0x170 net/ipv6/ip6_fib.c:1634 fib6_table_lookup+0xb7/0xa20 net/ipv6/route.c:2186 ip6_pol_route+0x1e1/0x1190 net/ipv6/route.c:2229 pol_lookup_func include/net/ip6_fib.h:583 [inline] fib6_rule_lookup+0x111/0x6f0 net/ipv6/fib6_rules.c:115 ip6_route_output_flags_noref+0x2c2/0x360 net/ipv6/route.c:2510 ip6_route_output_flags+0x8b/0x310 net/ipv6/route.c:2523 ip6_dst_lookup_tail+0x5b9/0x1700 net/ipv6/ip6_output.c:1053 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1156 sctp_v6_get_dst+0xfcc/0x1bb0 net/sctp/ipv6.c:337 sctp_transport_route+0x125/0x350 net/sctp/transport.c:297 sctp_packet_config+0x973/0xd20 net/sctp/output.c:103 sctp_outq_select_transport+0x1e4/0x740 net/sctp/outqueue.c:859 sctp_outq_flush_ctrl.constprop.0+0x291/0xc40 net/sctp/outqueue.c:893 sctp_outq_flush+0xfb/0x2380 net/sctp/outqueue.c:1186 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1801 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline] sctp_do_sm+0x4d0/0x4d80 net/sctp/sm_sideeffect.c:1156 sctp_generate_heartbeat_event+0x214/0x450 net/sctp/sm_sideeffect.c:391 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+0x1f7/0xa91 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+0x235/0x280 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x4d/0x90 kernel/locking/spinlock.c:191 Code: 48 c7 c0 48 3c b6 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 3c 48 83 3d 62 07 bf 01 00 74 29 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 44 80 58 f9 65 8b 05 7d c9 0a 78 RSP: 0018:ffffc900093a70f8 EFLAGS: 00000282 RAX: 1ffffffff136c789 RBX: 0000000000000282 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffffffff8cc2ec70 R08: 0000000000000001 R09: ffffffff8c5f5a9f R10: fffffbfff18beb53 R11: 1ffffffff137b368 R12: ffff88803e378d58 R13: dffffc0000000000 R14: 1ffff92001274e24 R15: ffffffff89bd68c0 debug_object_activate+0x1b3/0x3e0 lib/debugobjects.c:670 debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline] __call_rcu kernel/rcu/tree.c:2880 [inline] call_rcu+0x2c/0x7b0 kernel/rcu/tree.c:2968 dst_release net/core/dst.c:179 [inline] dst_release+0x79/0xe0 net/core/dst.c:169 sctp_v4_get_dst+0x845/0x1130 net/sctp/protocol.c:476 sctp_transport_route+0x125/0x350 net/sctp/transport.c:297 sctp_assoc_add_peer+0x60c/0x10b0 net/sctp/associola.c:659 sctp_process_param net/sctp/sm_make_chunk.c:2520 [inline] sctp_process_init+0x21c7/0x2840 net/sctp/sm_make_chunk.c:2341 sctp_cmd_process_init net/sctp/sm_sideeffect.c:670 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1377 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline] sctp_do_sm+0x2b9f/0x4d80 net/sctp/sm_sideeffect.c:1156 sctp_assoc_bh_rcv+0x386/0x6c0 net/sctp/associola.c:1044 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x19e/0x5c0 net/sctp/input.c:344 sk_backlog_rcv include/net/sock.h:1011 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2542 release_sock+0x54/0x1b0 net/core/sock.c:3065 sctp_wait_for_connect+0x30f/0x540 net/sctp/socket.c:9061 __sctp_connect+0x96b/0xc00 net/sctp/socket.c:1230 __sctp_setsockopt_connectx net/sctp/socket.c:1319 [inline] __sctp_setsockopt_connectx+0xfa/0x140 net/sctp/socket.c:1294 sctp_setsockopt_connectx_old net/sctp/socket.c:1330 [inline] sctp_setsockopt+0x1b69/0x97f0 net/sctp/socket.c:4482 __sys_setsockopt+0x2db/0x610 net/socket.c:2132 __do_sys_setsockopt net/socket.c:2143 [inline] __se_sys_setsockopt net/socket.c:2140 [inline] __ia32_sys_setsockopt+0xb9/0x150 net/socket.c:2140 do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline] __do_fast_syscall_32+0x60/0x90 arch/x86/entry/common.c:137 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:160 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7f20549 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f551a0cc EFLAGS: 00000296 ORIG_RAX: 000000000000016e RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000000084 RDX: 000000000000006b RSI: 000000002055bfe4 RDI: 000000000000001c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000