INFO: rcu_preempt self-detected stall on CPU 1-...: (1 GPs behind) idle=4f6/140000000000002/0 softirq=12610/12611 fqs=9 (t=10500 jiffies g=1984 c=1983 q=383) rcu_preempt kthread starved for 10481 jiffies! g1984 c1983 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29920 8 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 NMI backtrace for cpu 1 CPU: 1 PID: 7925 Comm: syz-executor.5 Not tainted 4.14.176-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline] rcu_dump_cpu_stacks+0x16d/0x1b8 kernel/rcu/tree.c:1396 print_cpu_stall kernel/rcu/tree.c:1542 [inline] check_cpu_stall kernel/rcu/tree.c:1610 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0x490/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:unwind_next_frame+0xaa0/0x17a0 arch/x86/kernel/unwind_orc.c:467 RSP: 0018:ffff8880aeb075d8 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff11d13d8 RBX: ffff8880aeb07720 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffff8880aeb07590 RDI: ffff8880aeb077a0 RBP: 1ffff11015d60ec2 R08: ffffffff88e89ec2 R09: ffff8880aeb07798 R10: ffff8880aeb07755 R11: 0000000000058071 R12: ffffffff88e89ebe R13: ffff8880aeb07758 R14: ffff8880aeb077a8 R15: 0000000000000002 __unwind_start arch/x86/kernel/unwind_orc.c:578 [inline] __unwind_start+0x450/0x800 arch/x86/kernel/unwind_orc.c:508 unwind_start arch/x86/include/asm/unwind.h:60 [inline] __save_stack_trace+0x4a/0xd0 arch/x86/kernel/stacktrace.c:43 save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc mm/slab.c:3390 [inline] kmem_cache_alloc+0x114/0x770 mm/slab.c:3550 dst_alloc+0xe6/0x190 net/core/dst.c:107 __ip6_dst_alloc+0x2e/0x50 net/ipv6/route.c:357 ip6_dst_alloc+0x2a/0x1d0 net/ipv6/route.c:370 icmp6_dst_alloc+0x155/0x580 net/ipv6/route.c:1766 ndisc_send_skb+0xc0f/0x11e0 net/ipv6/ndisc.c:463 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677 addrconf_rs_timer+0x289/0x5a0 net/ipv6/addrconf.c:3765 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:preempt_schedule_irq+0xa6/0x140 kernel/sched/core.c:3611 RSP: 0018:ffff8880503d7990 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff0fa2cd3 RBX: dffffc0000000000 RCX: 1ffff1100a079e00 RDX: 0000000000000000 RSI: ffff8880503cefe0 RDI: ffff8880503cef3c RBP: ffffed100a079cd8 R08: 00000022bc441e74 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880503ce6c0 R13: ffffffff87d16698 R14: 0000000000000000 R15: 0000000000000000 retint_kernel+0x1b/0x2d RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x50 kernel/kcov.c:88 RSP: 0018:ffff8880503d7a60 EFLAGS: 00000216 ORIG_RAX: ffffffffffffff10 RAX: 0000000000040000 RBX: ffff88812fffa000 RCX: ffffc9000766e000 RDX: 0000000000040000 RSI: ffffffff8129ba04 RDI: 0000778000000000 RBP: ffff88812fffa140 R08: dffffc0000000000 R09: ffffed100a07af62 R10: ffffed100a07af61 R11: ffff8880503d7b0f R12: 0000000000000001 R13: ffff88821636fa40 R14: ffff8880503d7b10 R15: 0000000000000000 valid_section include/linux/mmzone.h:1205 [inline] pfn_valid include/linux/mmzone.h:1242 [inline] __virt_addr_valid+0x144/0x1e0 arch/x86/mm/physaddr.c:64 check_heap_object mm/usercopy.c:204 [inline] __check_object_size mm/usercopy.c:242 [inline] __check_object_size+0x56/0x28a mm/usercopy.c:228 check_object_size include/linux/thread_info.h:108 [inline] __copy_from_user_inatomic include/linux/uaccess.h:65 [inline] __probe_kernel_read+0xda/0x1c0 mm/maccess.c:33 kmem_cache_sanity_check mm/slab_common.c:95 [inline] kmem_cache_create+0x8c/0x260 mm/slab_common.c:446 create_pid_cachep kernel/pid_namespace.c:56 [inline] create_pid_namespace kernel/pid_namespace.c:124 [inline] copy_pid_ns+0x6f5/0xa70 kernel/pid_namespace.c:186 create_new_namespaces+0x25f/0x730 kernel/nsproxy.c:94 copy_namespaces+0x27b/0x310 kernel/nsproxy.c:165 copy_process.part.0+0x2603/0x6a70 kernel/fork.c:1774 copy_process kernel/fork.c:1586 [inline] _do_fork+0x180/0xc80 kernel/fork.c:2070 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007fc996466c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00000000004da840 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000030020100 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000076 R14: 00000000004c311e R15: 00007fc9964676d4 INFO: rcu_sched detected stalls on CPUs/tasks: 1-...: (1 GPs behind) idle=4f6/140000000000001/0 softirq=12598/12611 fqs=2 (detected by 0, t=10559 jiffies, g=765, c=764, q=1) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3651 Comm: kworker/1:3 Not tainted 4.14.176-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient neigh_periodic_work task: ffff88808b7c4340 task.stack: ffff88808b7c8000 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:111 [inline] RIP: 0010:unwind_next_frame+0x533/0x17a0 arch/x86/kernel/unwind_orc.c:348 RSP: 0018:ffff88808b7cf800 EFLAGS: 00000a03 RAX: 0000000000003b68 RBX: ffff88808b7cf8b0 RCX: 0000000000003b68 RDX: ffffffff8956fcdc RSI: 0000000000000000 RDI: ffffffff8956fcdc RBP: 1ffff110116f9f07 R08: 0000000000000001 R09: ffff88808b7cfcf0 R10: ffff88808b7cf8e5 R11: 0000000000058071 R12: ffffffff813b68e2 R13: ffff88808b7cf8e8 R14: ffff88808b7cf8f8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31238000 CR3: 000000009ebc4000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 kmem_cache_alloc_node+0x148/0x7a0 mm/slab.c:3642 __alloc_skb+0x9a/0x4c0 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:980 [inline] nlmsg_new include/net/netlink.h:511 [inline] __neigh_notify+0x84/0x150 net/core/neighbour.c:2926 neigh_cleanup_and_release+0x71/0xc0 net/core/neighbour.c:106 neigh_periodic_work+0x489/0x8a0 net/core/neighbour.c:843 process_one_work+0x813/0x1540 kernel/workqueue.c:2116 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: ff 39 d0 0f 83 95 04 00 00 48 ba 00 00 00 00 00 fc ff df 89 c1 48 8d 3c 8d 3c 0f 56 89 48 89 fe 48 c1 ee 03 0f b6 34 16 48 89 fa <83> e2 07 83 c2 03 40 38 f2 7c 09 40 84 f6 0f 85 f0 0d 00 00 8d rcu_sched kthread starved for 10555 jiffies! g765 c764 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_sched R running task 29984 9 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404