Kernel panics at inet6addr_event() of 'ib_core'

Issue

• Kernel panic with below message from the logs.

:[505367.952168] BUG: unable to handle kernel NULL pointer dereference at 00000000000001c4
:[505367.952197] IP: [<ffffffffc07538b2>] inet6addr_event+0x32/0x60 [ib_core]
:[505367.952234] PGD 8000017d767c3067 PUD 1783838f067 PMD 0 
:[505367.952253] Oops: 0000 [#1] SMP 
:[505367.952268] Modules linked in: 8021q garp mrp stp llc nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache tracedev(OE) ib_ucm(OE) ib_cm(OE) ib_uverbs(OE) ib_umad(OE) ib_core(OE) mlx_compat(OE) ipt_REJECT nf_reject_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 xt_comment xt_multiport xt_conntrack nf_conntrack libcrc32c iptable_filter dcdbas iTCO_wdt iTCO_vendor_support mxm_wmi sb_edac edac_core intel_powerclamp coretemp intel_rapl iosf_mbi kvm_intel kvm irqbypass crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd pcspkr joydev mei_me sg mei lpc_ich shpchp acpi_power_meter wmi binfmt_misc nfsd nfs_acl lockd grace auth_rpcgss sunrpc ip_tables ext4 mbcache jbd2 sd_mod crc_t10dif crct10dif_generic mgag200 drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm
:[505367.954315]  crct10dif_pclmul ixgbe crct10dif_common crc32c_intel mlx4_core igb ahci libahci libata megaraid_sas mdio ptp i2c_algo_bit i2c_core pps_core devlink dca dm_mirror dm_region_hash dm_log dm_mod [last unloaded: mmfslinux]
:[505367.956241] CPU: 39 PID: 48773 Comm: ip Tainted: G           OE  ------------   3.10.0-693.17.1.el7.x86_64 #1
:[505367.956918] Hardware name: Dell Inc. PowerEdge R630/02C2CP, BIOS 2.6.0 10/26/2017
:[505367.957601] task: ffff8976cab63f40 ti: ffff897d68698000 task.ti: ffff897d68698000
:[505367.958290] RIP: 0010:[<ffffffffc07538b2>]  [<ffffffffc07538b2>] inet6addr_event+0x32/0x60 [ib_core]
:[505367.958999] RSP: 0018:ffff897d6869b490  EFLAGS: 00010286
:[505367.959708] RAX: ffff88bd46f681c0 RBX: 00000000ffffffff RCX: 00000000ffffffff
:[505367.960431] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffffc0772eb0
:[505367.961156] RBP: ffff897d6869b4b0 R08: 0000000000000000 R09: 00000000000080fe
:[505367.961884] R10: e8ea38feff966e26 R11: 0000000000004c10 R12: 0000000000000000
:[505367.962616] R13: 0000000000000002 R14: ffff88bd7bd5c600 R15: 0000000000000000
:[505367.963356] FS:  00007fd73569a740(0000) GS:ffff897d7e2c0000(0000) knlGS:0000000000000000
:[505367.964103] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
:[505367.964855] CR2: 00000000000001c4 CR3: 00000178e8e0e000 CR4: 00000000003607e0
:[505367.965609] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
:[505367.966357] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
:[505367.967097] Call Trace:
:[505367.967840]  [<ffffffff816b3d0c>] notifier_call_chain+0x4c/0x70
:[505367.968588]  [<ffffffff816b3d6a>] atomic_notifier_call_chain+0x1a/0x20
:[505367.969342]  [<ffffffff8167e03b>] inet6addr_notifier_call_chain+0x1b/0x20
:[505367.970093]  [<ffffffff8164db4b>] addrconf_ifdown+0x22b/0x3e0
:[505367.970837]  [<ffffffff8164eae2>] addrconf_notify+0x1d2/0xa90
:[505367.971576]  [<ffffffff816ade8e>] ? _raw_spin_unlock_bh+0x1e/0x20
:[505367.972297]  [<ffffffff816b3d0c>] notifier_call_chain+0x4c/0x70
:[505367.973002]  [<ffffffff810b8656>] raw_notifier_call_chain+0x16/0x20
:[505367.973714]  [<ffffffff8158506d>] call_netdevice_notifiers_info+0x4d/0x80
:[505367.974420]  [<ffffffff8158d0ba>] __dev_notify_flags+0x8a/0xe0
:[505367.975120]  [<ffffffff8158d8f2>] dev_change_flags+0x52/0x60
:[505367.975813]  [<ffffffff8159e206>] do_setlink+0x366/0xe20
:[505367.976502]  [<ffffffff8118e39a>] ? get_page_from_freelist+0x4fa/0x9e0
:[505367.977204]  [<ffffffff815a093c>] rtnl_newlink+0x50c/0x850
:[505367.977900]  [<ffffffff815a0523>] ? rtnl_newlink+0xf3/0x850
:[505367.978594]  [<ffffffff816b3b15>] ? do_page_fault+0x35/0x90
:[505367.979292]  [<ffffffff812b3da8>] ? security_capable+0x18/0x20
:[505367.979987]  [<ffffffff81096869>] ? ns_capable+0x29/0x50
:[505367.980674]  [<ffffffff8159bbf4>] rtnetlink_rcv_msg+0xa4/0x270
:[505367.981355]  [<ffffffff811e41d8>] ? __kmalloc_node_track_caller+0x58/0x290
:[505367.982033]  [<ffffffff812b405e>] ? security_inode_alloc+0x1e/0x20
:[505367.982708]  [<ffffffff815bcd10>] ? __netlink_lookup+0xc0/0x110
:[505367.983379]  [<ffffffff8159bb50>] ? rtnetlink_rcv+0x30/0x30
:[505367.984034]  [<ffffffff815bf969>] netlink_rcv_skb+0xa9/0xc0
:[505367.984667]  [<ffffffff8159bb48>] rtnetlink_rcv+0x28/0x30
:[505367.985282]  [<ffffffff815bf052>] netlink_unicast+0xf2/0x1b0
:[505367.985880]  [<ffffffff815bf42f>] netlink_sendmsg+0x31f/0x6a0
:[505367.986458]  [<ffffffff81248e4e>] ? fsnotify_destroy_marks+0x6e/0x90
:[505367.987022]  [<ffffffff8156c580>] sock_sendmsg+0xb0/0xf0
:[505367.987567]  [<ffffffff81278c42>] ? proc_lookup_de+0xb2/0xc0
:[505367.988093]  [<ffffffff8156ce29>] ___sys_sendmsg+0x3a9/0x3c0
:[505367.988601]  [<ffffffff811f4f52>] ? __mem_cgroup_commit_charge+0xe2/0x2f0
:[505367.989102]  [<ffffffff811be478>] ? page_add_new_anon_rmap+0xb8/0x170
:[505367.989591]  [<ffffffff811b4178>] ? handle_mm_fault+0x858/0xfa0
:[505367.990073]  [<ffffffff8121a914>] ? dentry_kill+0x154/0x1b0
:[505367.990542]  [<ffffffff8156d5f1>] __sys_sendmsg+0x51/0x90
:[505367.990999]  [<ffffffff8156d642>] SyS_sendmsg+0x12/0x20
:[505367.991449]  [<ffffffff816b89fd>] system_call_fastpath+0x16/0x1b
:[505367.991897] Code: 0a 00 00 00 48 89 e5 48 83 ec 20 4c 8b 0a 66 89 44 24 04 4c 8b 52 08 48 8b 82 c8 00 00 00 4c 89 4c 24 0c 4c 89 54 24 14 48 8b 10 <66> 83 ba c4 01 00 00 01 74 04 31 c0 c9 c3 48 89 f7 48 8d 74 24 
:[505367.992892] RIP  [<ffffffffc07538b2>] inet6addr_event+0x32/0x60 [ib_core]
:[505367.993382]  RSP <ffff897d6869b490>
:[505367.993857] CR2: 00000000000001c4