rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=b66/1/0x4000000000000004 softirq=15450/15450 fqs=0 (t=10500 jiffies g=16873 q=1022) rcu: rcu_preempt kthread starved for 10500 jiffies! g16873 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I29440 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xd9/0x260 kernel/sched/core.c:3947 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 10941 Comm: syz-executor.1 Not tainted 5.3.0-rc7+ #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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2736 [inline] rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:hhf_dequeue+0x572/0xa20 net/sched/sch_hhf.c:436 Code: 48 39 c2 74 34 e8 fe 94 aa fb 49 8d bd ac 03 00 00 48 89 f8 48 c1 e8 03 42 0f b6 14 20 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 b5 03 00 00 45 8b b5 ac 03 00 00 e8 ca 94 aa fb 49 8d RSP: 0018:ffff8880ae809058 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff8880919770b8 RCX: ffffffff85c7dbb9 RDX: 0000000000000000 RSI: ffffffff85c7e052 RDI: ffff88809197716c RBP: ffff8880ae8090a8 R08: ffff8880a99723c0 R09: fffffbfff14e9555 R10: ffff8880a9972d90 R11: ffff8880a99723c0 R12: dffffc0000000000 R13: ffff888091976dc0 R14: 0000000000000001 R15: 0000000000000000 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x16f1/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] __br_forward+0x641/0xb00 net/bridge/br_forward.c:109 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125 maybe_deliver+0x2c7/0x390 net/bridge/br_forward.c:181 br_flood+0x13a/0x3d0 net/bridge/br_forward.c:223 br_dev_xmit+0xd33/0x15a0 net/bridge/br_device.c:84 __netdev_start_xmit include/linux/netdevice.h:4419 [inline] netdev_start_xmit include/linux/netdevice.h:4433 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 arp_xmit_finish net/ipv4/arp.c:630 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] arp_xmit+0xdf/0x3f0 net/ipv4/arp.c:639 arp_send_dst.part.0+0x202/0x280 net/ipv4/arp.c:317 arp_send_dst net/ipv4/arp.c:390 [inline] arp_solicit+0x752/0x1380 net/ipv4/arp.c:389 neigh_probe+0xc6/0x110 net/core/neighbour.c:1012 neigh_timer_handler+0x59d/0xf60 net/core/neighbour.c:1093 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:unwind_next_frame+0x0/0x50 arch/x86/kernel/unwind_frame.c:265 Code: a6 1b 7b 00 4c 8b 95 60 ff ff ff 4c 8b 9d 68 ff ff ff 4c 8b 8d 70 ff ff ff e9 b7 fb ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 c1 ea 03 48 89 e5 48 RSP: 0018:ffff8880674df318 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffffff81616b40 RCX: ffffc90008172000 RDX: 0000000000040000 RSI: ffffffff81616c6e RDI: ffff8880674df320 RBP: ffff8880674df3a8 R08: ffff8880a99723c0 R09: ffff8880674df378 R10: ffff8880674df348 R11: ffff8880674df358 R12: ffff8880674df3d8 R13: 0000000000000000 R14: ffff8880a99723c0 R15: ffff8880a99aca80 stack_trace_save+0xac/0xe0 kernel/stacktrace.c:123 save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:493 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:501 slab_post_alloc_hook mm/slab.h:520 [inline] slab_alloc_node mm/slab.c:3262 [inline] kmem_cache_alloc_node+0x138/0x740 mm/slab.c:3574 __alloc_skb+0xd5/0x5e0 net/core/skbuff.c:197 alloc_skb include/linux/skbuff.h:1053 [inline] alloc_uevent_skb+0x83/0x1e2 lib/kobject_uevent.c:289 uevent_net_broadcast_tagged lib/kobject_uevent.c:350 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:411 [inline] kobject_uevent_env+0xbd6/0x101d lib/kobject_uevent.c:592 kobject_uevent+0x20/0x26 lib/kobject_uevent.c:641 netdev_queue_add_kobject net/core/net-sysfs.c:1476 [inline] netdev_queue_update_kobjects+0x2ff/0x3d0 net/core/net-sysfs.c:1490 register_queue_kobjects net/core/net-sysfs.c:1532 [inline] netdev_register_kobject+0x29b/0x3b0 net/core/net-sysfs.c:1750 register_netdevice+0x875/0xf10 net/core/dev.c:8777 __ip_tunnel_create+0x36b/0x530 net/ipv4/ip_tunnel.c:269 ip_tunnel_init_net+0x375/0x9e0 net/ipv4/ip_tunnel.c:1060 ipgre_init_net+0x25/0x30 net/ipv4/ip_gre.c:988 ops_init+0xb3/0x420 net/core/net_namespace.c:137 setup_net+0x2cc/0x880 net/core/net_namespace.c:334 copy_net_ns+0x290/0x41f net/core/net_namespace.c:475 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:103 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202 ksys_unshare+0x444/0x980 kernel/fork.c:2831 __do_sys_unshare kernel/fork.c:2899 [inline] __se_sys_unshare kernel/fork.c:2897 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2897 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc2ce141c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc2ce1426d4 R13: 00000000004c9090 R14: 00000000004e0290 R15: 00000000ffffffff