Hi linux experts,
We encounter one panic on kernel v4.4.60 when doing igmp6_send() && __neigh_create(),
the crash dump is append as below.
Any one experience in this, or any bug fix can be applied??

Thanks!





[ 168.046489] NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [swapper/1:0]
[ 168.046525] Modules linked in: ecm smart_antenna(P) ath_pktlog(P) wifi_2_0 wifi_3_0 qca_ol qca_spectral umac asf(P) qdf mem_manager(P) iptable_nat rndis_host pppoe nf_nat_pptp nf_nat_ipv4 nf_nat_amanda nf_conntrack_pptp nf_conntrack_ipv6 nf_conntrack_ipv4 nf_conntrack_amanda l2tp_ppp ipt_REJECT ipt_MASQUERADE cdc_ether xt_time xt_tcpudp xt_tcpmss xt_string xt_statistic xt_state xt_recent xt_quota xt_policy xt_pkttype xt_physdev xt_owner xt_nat xt_multiport xt_mark xt_mac xt_limit xt_length xt_id xt_hl xt_helper xt_esp xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit xt_connbytes xt_comment xt_addrtype xt_TCPMSS xt_REDIRECT xt_LOG xt_HL xt_DSCP xt_CT xt_CLASSIFY usbnet ts_kmp ts_fsm ts_bm pptp pppox ppp_mppe ppp_async nf_reject_ipv4 nf_nat_tftp nf_nat_snmp_basic nf_nat_sip nf_nat_rtsp nf_nat_redirect nf_nat_proto_gre nf_nat_masquerade_ipv4 nf_nat_irc nf_nat_h323 nf_nat_ftp nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_tftp nf_conntrack_snmp nf_conntrack_sip nf_conntrack_rtsp nf_conntrack_rtcache nf_conntrack_proto_gre nf_conntrack_irc nf_conntrack_h323 nf_conntrack_ftp nf_conntrack_broadcast iptable_raw iptable_mangle iptable_filter ipt_ah ipt_ECN ip_tables arptable_filter arpt_mangle arp_tables fuse sch_teql sch_tbf sch_sfq sch_red sch_prio sch_pie sch_htb sch_gred sch_fq sch_dsmark sch_codel em_text em_nbyte em_meta em_cmp cls_basic act_police act_ipt act_connmark act_skbedit act_mirred em_u32 cls_u32 cls_tcindex cls_flow cls_route cls_fw sch_hfsc sch_ingress qca_mcs hyfi_bridging nf_nat_proto_sctp nf_nat libcrc32c nf_conntrack_proto_sctp essedma ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_raw ip6table_mangle ip6table_filter ip6_tables x_tables hyfi_qdisc msdos bonding ip_gre gre ifb nat46 sit l2tp_netlink l2tp_core udp_tunnel ip6_udp_tunnel ipcomp6 xfrm6_tunnel xfrm6_mode_tunnel xfrm6_mode_transport xfrm6_mode_beet esp6 ah6 ipcomp xfrm4_tunnel xfrm4_mode_tunnel xfrm4_mode_transport xfrm4_mode_beet esp4 ah4 ip6_tunnel tunnel6 tunnel4 ip_tunnel tun qca_ssdk ppp_generic slhc af_key xfrm_user xfrm_ipcomp xfrm_algo vfat fat ntfs cfg80211 qrfs nf_conntrack nls_iso8859_1 nls_cp437 shortcut_fe_drv shortcut_fe_ipv6 shortcut_fe sha1_generic qcrypto cryptosoft cryptodev ocf md5 ecb des_generic cbc authenc uas usb_storage leds_gpio bootconfig xhci_plat_hcd xhci_pci xhci_hcd dwc3 dwc3_of_simple dbm phy_qca_uniphy phy_qca_baldur ahci ehci_platform ehci_hcd sd_mod ahci_platform libahci_platform libahci libata scsi_mod gpio_button_hotplug button_hotplug input_core usbcore mii
[ 168.273086] CPU: 1 PID: 0 Comm: swapper/1 Tainted: P 4.4.60 #9
[ 168.273439] Hardware name: Qualcomm (Flattened Device Tree)
[ 168.280560] task: df45b700 ti: df48a000 task.ti: df48a000
[ 168.285946] PC is at _raw_write_lock_bh+0x30/0x44
[ 168.291495] LR is at __neigh_create+0x380/0x5b8
[ 168.296181] pc : [<c030a7a0>] lr : [<c06b9544>] psr: a0000113
[ 168.296181] sp : df48bd30 ip : 00000001 fp : c0b4d44c
[ 168.300529] r10: 0105d511 r9 : 01000000 r8 : 00000001
[ 168.311980] r7 : d9e6f800 r6 : d8672a00 r5 : c0b4d448 r4 : c0b4d334
[ 168.317189] r3 : 80000000 r2 : 80000000 r1 : d8672a60 r0 : c0b4d44c
[ 168.323788] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
[ 168.330299] Control: 10c5387d Table: 987f406a DAC: 00000055
[ 168.337503] CPU: 1 PID: 0 Comm: swapper/1 Tainted: P 4.4.60 #9
[ 168.343403] Hardware name: Qualcomm (Flattened Device Tree)
[ 168.350544] [<c0316d2c>] (unwind_backtrace) from [<c0313680>] (show_stack+0x10/0x14)
[ 168.355918] [<c0313680>] (show_stack) from [<c0510274>] (dump_stack+0x7c/0x9c)
[ 168.363905] [<c0510274>] (dump_stack) from [<c038f1f4>] (watchdog_timer_fn+0x19c/0x224)
[ 168.370936] [<c038f1f4>] (watchdog_timer_fn) from [<c036ad04>] (__hrtimer_run_queues+0xb4/0x140)
[ 168.378835] [<c036ad04>] (__hrtimer_run_queues) from [<c036b288>] (hrtimer_interrupt+0xb0/0x1f8)
[ 168.387863] [<c036b288>] (hrtimer_interrupt) from [<c0653658>] (arch_timer_handler_virt+0x28/0x30)
[ 168.396632] [<c0653658>] (arch_timer_handler_virt) from [<c035ffa0>] (handle_percpu_devid_irq+0x68/0x84)
[ 168.405401] [<c035ffa0>] (handle_percpu_devid_irq) from [<c035c27c>] (generic_handle_irq+0x18/0x28)
[ 168.415033] [<c035c27c>] (generic_handle_irq) from [<c035c540>] (__handle_domain_irq+0x8c/0xb4)
[ 168.423799] [<c035c540>] (__handle_domain_irq) from [<c030137c>] (gic_handle_irq+0x50/0x94)
[ 168.432480] [<c030137c>] (gic_handle_irq) from [<c03024c0>] (__irq_svc+0x40/0x74)
[ 168.440802] Exception stack(0xdf48bce0 to 0xdf48bd28)
[ 168.448444] bce0: c0b4d44c d8672a60 80000000 80000000 c0b4d334 c0b4d448 d8672a00 d9e6f800
[ 168.453484] bd00: 00000001 01000000 0105d511 c0b4d44c 00000001 df48bd30 c06b9544 c030a7a0
[ 168.461637] bd20: a0000113 ffffffff
[ 168.469798] [<c03024c0>] (__irq_svc) from [<c030a7a0>] (_raw_write_lock_bh+0x30/0x44)
[ 168.473105] [<c030a7a0>] (_raw_write_lock_bh) from [<c06b9544>] (__neigh_create+0x380/0x5b8)
[ 168.481094] [<c06b9544>] (__neigh_create) from [<c073d9f8>] (ip6_finish_output2+0x42c/0x644)
[ 168.489599] [<c073d9f8>] (ip6_finish_output2) from [<c07416e0>] (ip6_output+0x128/0x19c)
[ 168.498017] [<c07416e0>] (ip6_output) from [<c0760fc0>] (igmp6_send+0x408/0x624)
[ 168.506088] [<c0760fc0>] (igmp6_send) from [<c0761a78>] (igmp6_timer_handler+0x2c/0x6c)
[ 168.513466] [<c0761a78>] (igmp6_timer_handler) from [<c0369690>] (call_timer_fn+0x20/0x90)
[ 168.521191] [<c0369690>] (call_timer_fn) from [<c0369894>] (run_timer_softirq+0x194/0x1c0)
[ 168.529526] [<c0369894>] (run_timer_softirq) from [<c03247e8>] (__do_softirq+0xe4/0x228)
[ 168.537775] [<c03247e8>] (__do_softirq) from [<c0324bc8>] (irq_exit+0x98/0x108)
[ 168.546020] [<c0324bc8>] (irq_exit) from [<c035c544>] (__handle_domain_irq+0x90/0xb4)
[ 168.553051] [<c035c544>] (__handle_domain_irq) from [<c030137c>] (gic_handle_irq+0x50/0x94)
[ 168.561037] [<c030137c>] (gic_handle_irq) from [<c03024c0>] (__irq_svc+0x40/0x74)
[ 168.569186] Exception stack(0xdf48bf98 to 0xdf48bfe0)
[ 168.576823] bf80: 00000001 00000000
[ 168.581869] bfa0: 00000000 c0303360 00000000 df48a000 00000000 c0a3134c df48bff0 410fc075
[ 168.590028] bfc0: 00000000 00000000 1f114000 df48bfe8 c0310d7c c0310d80 60000013 ffffffff
[ 168.598190] [<c03024c0>] (__irq_svc) from [<c0310d80>] (arch_cpu_idle+0x2c/0x50)
[ 168.606350] [<c0310d80>] (arch_cpu_idle) from [<c0354178>] (cpu_startup_entry+0x134/0x214)
[ 168.613815] [<c0354178>] (cpu_startup_entry) from [<8030144c>] (0x8030144c)
[ 169.445723] INFO: rcu_preempt self-detected stall on CPU
[ 169.445737] INFO: rcu_preempt self-detected stall on CPU
[ 169.445750] 1-...: (1 GPs behind) idle=2c9/2/0 softirq=12700/12701 fqs=1037
[ 169.445760] (t=2100 jiffies g=5114 c=5113 q=1704)
[ 169.445769] rcu_preempt kthread starved for 1061 jiffies! g5114 c5113 f0x0 s3 ->state=0x1
[ 169.445772] Task dump for CPU 1:
[ 169.445781] swapper/1 R running 0 0 1 0x00000002
[ 169.445808] [<c0316d2c>] (unwind_backtrace) from [<c0313680>] (show_stack+0x10/0x14)
[ 169.445823] [<c0313680>] (show_stack) from [<c03643dc>] (rcu_dump_cpu_stacks+0x74/0x98)
[ 169.445840] [<c03643dc>] (rcu_dump_cpu_stacks) from [<c0367a00>] (rcu_check_callbacks+0x278/0x794)
[ 169.445855] [<c0367a00>] (rcu_check_callbacks) from [<c036a3d4>] (update_process_times+0x30/0x5c)
[ 169.445870] [<c036a3d4>] (update_process_times) from [<c03785b0>] (tick_sched_timer+0x44/0x84)
[ 169.445885] [<c03785b0>] (tick_sched_timer) from [<c036ad04>] (__hrtimer_run_queues+0xb4/0x140)
[ 169.445898] [<c036ad04>] (__hrtimer_run_queues) from [<c036b288>] (hrtimer_interrupt+0xb0/0x1f8)
[ 169.445913] [<c036b288>] (hrtimer_interrupt) from [<c0653658>] (arch_timer_handler_virt+0x28/0x30)
[ 169.445929] [<c0653658>] (arch_timer_handler_virt) from [<c035ffa0>] (handle_percpu_devid_irq+0x68/0x84)
[ 169.445945] [<c035ffa0>] (handle_percpu_devid_irq) from [<c035c27c>] (generic_handle_irq+0x18/0x28)
[ 169.445961] [<c035c27c>] (generic_handle_irq) from [<c035c540>] (__handle_domain_irq+0x8c/0xb4)
[ 169.445975] [<c035c540>] (__handle_domain_irq) from [<c030137c>] (gic_handle_irq+0x50/0x94)
[ 169.445987] [<c030137c>] (gic_handle_irq) from [<c03024c0>] (__irq_svc+0x40/0x74)
[ 169.445992] Exception stack(0xdf48bce0 to 0xdf48bd28)
[ 169.446005] bce0: c0b4d44c d8672a60 80000000 80000000 c0b4d334 c0b4d448 d8672a00 d9e6f800
[ 169.446017] bd00: 00000001 01000000 0105d511 c0b4d44c 00000001 df48bd30 c06b9544 c030a7a0
[ 169.446023] bd20: a0000113 ffffffff
[ 169.446038] [<c03024c0>] (__irq_svc) from [<c030a7a0>] (_raw_write_lock_bh+0x30/0x44)
[ 169.446053] [<c030a7a0>] (_raw_write_lock_bh) from [<c06b9544>] (__neigh_create+0x380/0x5b8)
[ 169.446070] [<c06b9544>] (__neigh_create) from [<c073d9f8>] (ip6_finish_output2+0x42c/0x644)
[ 169.446086] [<c073d9f8>] (ip6_finish_output2) from [<c07416e0>] (ip6_output+0x128/0x19c)
[ 169.446099] [<c07416e0>] (ip6_output) from [<c0760fc0>] (igmp6_send+0x408/0x624)
[ 169.446112] [<c0760fc0>] (igmp6_send) from [<c0761a78>] (igmp6_timer_handler+0x2c/0x6c)
[ 169.446126] [<c0761a78>] (igmp6_timer_handler) from [<c0369690>] (call_timer_fn+0x20/0x90)
[ 169.446138] [<c0369690>] (call_timer_fn) from [<c0369894>] (run_timer_softirq+0x194/0x1c0)
[ 169.446150] [<c0369894>] (run_timer_softirq) from [<c03247e8>] (__do_softirq+0xe4/0x228)
[ 169.446162] [<c03247e8>] (__do_softirq) from [<c0324bc8>] (irq_exit+0x98/0x108)
[ 169.446175] [<c0324bc8>] (irq_exit) from [<c035c544>] (__handle_domain_irq+0x90/0xb4)
[ 169.446188] [<c035c544>] (__handle_domain_irq) from [<c030137c>] (gic_handle_irq+0x50/0x94)
[ 169.446201] [<c030137c>] (gic_handle_irq) from [<c03024c0>] (__irq_svc+0x40/0x74)
[ 169.446206] Exception stack(0xdf48bf98 to 0xdf48bfe0)
[ 169.446212] bf80: 00000001 00000000
[ 169.446224] bfa0: 00000000 c0303360 00000000 df48a000 00000000 c0a3134c df48bff0 410fc075
[ 169.446236] bfc0: 00000000 00000000 1f114000 df48bfe8 c0310d7c c0310d80 60000013 ffffffff
[ 169.446248] [<c03024c0>] (__irq_svc) from [<c0310d80>] (arch_cpu_idle+0x2c/0x50)
[ 169.446264] [<c0310d80>] (arch_cpu_idle) from [<c0354178>] (cpu_startup_entry+0x134/0x214)
[ 169.446276] [<c0354178>] (cpu_startup_entry) from [<8030144c>] (0x8030144c)
[ 169.446280] Task dump for CPU 3:
[ 169.446290] netifd R running 0 1731 1 0x00000002
[ 169.446301] [<c03071e4>] (__schedule) from [<000002ff>] (0x2ff)
[ 169.786563]
[ 169.792206] 3-...: (1 GPs behind) idle=8c3/140000000000001/0 softirq=11133/11139 fqs=1037
[ 169.793942] (t=2135 jiffies g=5114 c=5113 q=1704)
[ 169.803402] rcu_preempt kthread starved for 1096 jiffies! g5114 c5113 f0x0 s3 ->state=0x1
[ 169.806877] Task dump for CPU 1:
[ 169.815202] swapper/1 R running 0 0 1 0x00000002
[ 169.822082] [<c03071e4>] (__schedule) from [<c0310d80>] (arch_cpu_idle+0x2c/0x50)
[ 169.824681] [<c0310d80>] (arch_cpu_idle) from [<ffffffff>] (0xffffffff)
[ 169.832222] Task dump for CPU 3:
[ 169.838639] netifd R running 0 1731 1 0x00000002
[ 169.845685] [<c0316d2c>] (unwind_backtrace) from [<c0313680>] (show_stack+0x10/0x14)
[ 169.848296] [<c0313680>] (show_stack) from [<c03643dc>] (rcu_dump_cpu_stacks+0x74/0x98)
[ 169.856197] [<c03643dc>] (rcu_dump_cpu_stacks) from [<c0367a00>] (rcu_check_callbacks+0x278/0x794)
[ 169.863925] [<c0367a00>] (rcu_check_callbacks) from [<c036a3d4>] (update_process_times+0x30/0x5c)
[ 169.872949] [<c036a3d4>] (update_process_times) from [<c03785b0>] (tick_sched_timer+0x44/0x84)
[ 169.881889] [<c03785b0>] (tick_sched_timer) from [<c036ad04>] (__hrtimer_run_queues+0xb4/0x140)
[ 169.890395] [<c036ad04>] (__hrtimer_run_queues) from [<c036b288>] (hrtimer_interrupt+0xb0/0x1f8)
[ 169.898993] [<c036b288>] (hrtimer_interrupt) from [<c0653658>] (arch_timer_handler_virt+0x28/0x30)
[ 169.908021] [<c0653658>] (arch_timer_handler_virt) from [<c035ffa0>] (handle_percpu_devid_irq+0x68/0x84)
[ 169.916789] [<c035ffa0>] (handle_percpu_devid_irq) from [<c035c27c>] (generic_handle_irq+0x18/0x28)
[ 169.926421] [<c035c27c>] (generic_handle_irq) from [<c035c540>] (__handle_domain_irq+0x8c/0xb4)
[ 169.935188] [<c035c540>] (__handle_domain_irq) from [<c030137c>] (gic_handle_irq+0x50/0x94)
[ 169.943866] [<c030137c>] (gic_handle_irq) from [<c03024c0>] (__irq_svc+0x40/0x74)
[ 169.952190] Exception stack(0xd9213ba8 to 0xd9213bf0)
[ 169.959831] 3ba0: c0b4d44c d68fb860 80000000 80000000 c0b4d334 c0b4d448
[ 169.964872] 3bc0: d68fb800 d9e6f800 00000001 00000000 0105d511 c0b4d44c 00000001 d9213bf8
[ 169.973028] 3be0: c06b9544 c030a7a0 a0000013 ffffffff
[ 169.981192] [<c03024c0>] (__irq_svc) from [<c030a7a0>] (_raw_write_lock_bh+0x30/0x44)
[ 169.986229] [<c030a7a0>] (_raw_write_lock_bh) from [<c06b9544>] (__neigh_create+0x380/0x5b8)
[ 169.994045] [<c06b9544>] (__neigh_create) from [<c073d9f8>] (ip6_finish_output2+0x42c/0x644)
[ 170.002550] [<c073d9f8>] (ip6_finish_output2) from [<c07416e0>] (ip6_output+0x128/0x19c)
[ 170.010969] [<c07416e0>] (ip6_output) from [<c0760fc0>] (igmp6_send+0x408/0x624)
[ 170.019039] [<c0760fc0>] (igmp6_send) from [<c0761908>] (igmp6_group_dropped+0xc8/0x20c)
[ 170.026419] [<c0761908>] (igmp6_group_dropped) from [<c076277c>] (__ipv6_dev_mc_dec+0xb4/0xf4)
[ 170.034496] [<c076277c>] (__ipv6_dev_mc_dec) from [<c0755c1c>] (pndisc_destructor+0x58/0x78)
[ 170.042913] [<c0755c1c>] (pndisc_destructor) from [<c06b8e8c>] (neigh_ifdown+0x74/0xd8)
[ 170.051506] [<c06b8e8c>] (neigh_ifdown) from [<c0757450>] (ndisc_netdev_event+0x2c/0x120)
[ 170.059234] [<c0757450>] (ndisc_netdev_event) from [<c03398a8>] (notifier_call_chain+0x40/0x68)
[ 170.067570] [<c03398a8>] (notifier_call_chain) from [<c0339928>] (raw_notifier_call_chain+0x14/0x1c)
[ 170.076077] [<c0339928>] (raw_notifier_call_chain) from [<c06a86d0>] (call_netdevice_notifiers+0xc/0x14)
[ 170.085453] [<c06a86d0>] (call_netdevice_notifiers) from [<c06af8e8>] (__dev_notify_flags+0x48/0x88)
[ 170.094916] [<c06af8e8>] (__dev_notify_flags) from [<c06afe94>] (dev_change_flags+0x40/0x48)
[ 170.104029] [<c06afe94>] (dev_change_flags) from [<c06c3408>] (dev_ifsioc+0xd8/0x2d0)
[ 170.112444] [<c06c3408>] (dev_ifsioc) from [<c06c3c98>] (dev_ioctl+0x60c/0x6c4)
[ 170.120168] [<c06c3c98>] (dev_ioctl) from [<c03edd30>] (do_vfs_ioctl+0x4f0/0x5b0)
[ 170.127288] [<c03edd30>] (do_vfs_ioctl) from [<c03ede24>] (SyS_ioctl+0x34/0x5c)
[ 170.134922] [<c03ede24>] (SyS_ioctl) from [<c0301b80>] (ret_fast_syscall+0x0/0x34)