RHEL7: Kernel panic at nlm_destroy_host_locked

Issue

• Kernel panic with following log:

[1504481.008210] BUG: unable to handle kernel NULL pointer dereference at 0000000000000ce8
[1504481.009121] IP: [<ffffffffc0834a0e>] nlm_destroy_host_locked+0x1e/0xe0 [lockd]
[1504481.009997] PGD 0 
[1504481.010884] Oops: 0000 [#1] SMP 
[1504481.011700] Modules linked in: iptable_filter nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache vmw_vsock_vmci_transport vsock sunrpc ppdev vmw_balloon sb_edac iosf_mbi crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd joydev sg pcspkr parport_pc parport vmw_vmci i2c_piix4 binfmt_misc ip_tables xfs libcrc32c sr_mod sd_mod cdrom crc_t10dif crct10dif_generic ata_generic pata_acpi vmwgfx drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ata_piix libata crct10dif_pclmul crct10dif_common crc32c_intel serio_raw vmxnet3 vmw_pvscsi drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod
[1504481.016377] CPU: 3 PID: 21611 Comm: umount.nfs Kdump: loaded Tainted: G        W      ------------   3.10.0-957.21.3.el7.x86_64 #1
[1504481.017361] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015
[1504481.018365] task: ffff9705c62d6180 ti: ffff9708f8618000 task.ti: ffff9708f8618000
[1504481.019394] RIP: 0010:[<ffffffffc0834a0e>]  [<ffffffffc0834a0e>] nlm_destroy_host_locked+0x1e/0xe0 [lockd]
[1504481.020456] RSP: 0018:ffff9708f861be00  EFLAGS: 00010206
[1504481.021502] RAX: 0000000000000005 RBX: ffff97024c7fc800 RCX: 00000000c0000100
[1504481.022554] RDX: 0000000000000000 RSI: ffff9705c62d6180 RDI: ffff97024c7fc800
[1504481.023639] RBP: ffff9708f861be10 R08: ffff9708f8618000 R09: 0000000000000001
[1504481.024980] R10: 0000000000000000 R11: 0000000000000000 R12: ffff97099866c000
[1504481.026060] R13: ffff9705c62d6180 R14: ffffffffa2ae65b0 R15: ffff9705c62d6950
[1504481.027134] FS:  00002affd24c5240(0000) GS:ffff970a7fd80000(0000) knlGS:0000000000000000
[1504481.028224] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1504481.029302] CR2: 0000000000000ce8 CR3: 00000004b8086000 CR4: 00000000003607e0
[1504481.030469] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1504481.031568] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[1504481.032627] Call Trace:
[1504481.033636]  [<ffffffffc0834cfa>] nlmclnt_release_host+0x8a/0x160 [lockd]
[1504481.034646]  [<ffffffffc08320d6>] nlmclnt_done+0x16/0x30 [lockd]
[1504481.035634]  [<ffffffffc084a637>] nfs_destroy_server+0x17/0x20 [nfs]
[1504481.036570]  [<ffffffffc084b396>] nfs_free_server+0x36/0xd0 [nfs]
[1504481.037484]  [<ffffffffc08580eb>] nfs_kill_super+0x2b/0x30 [nfs]
[1504481.038403]  [<ffffffffa1c44aee>] deactivate_locked_super+0x4e/0x70
[1504481.039301]  [<ffffffffa1c45276>] deactivate_super+0x46/0x60
[1504481.040176]  [<ffffffffa1c6387f>] cleanup_mnt+0x3f/0x80
[1504481.041037]  [<ffffffffa1c63912>] __cleanup_mnt+0x12/0x20
[1504481.041923]  [<ffffffffa1abe90b>] task_work_run+0xbb/0xe0
[1504481.042805]  [<ffffffffa1a2bc65>] do_notify_resume+0xa5/0xc0
[1504481.043682]  [<ffffffffa2176134>] int_signal+0x12/0x17
[1504481.044558] Code: e8 5f 7f 92 e1 eb df 66 0f 1f 44 00 00 0f 1f 44 00 00 55 8b 05 a4 f3 00 00 48 89 e5 41 54 53 48 89 fb 48 8b 97 00 02 00 00 85 c0 <48> 8b 92 e8 0c 00 00 0f 84 8b 00 00 00 3b 02 0f 87 83 00 00 00 
[1504481.046477] RIP  [<ffffffffc0834a0e>] nlm_destroy_host_locked+0x1e/0xe0 [lockd]
[1504481.047402]  RSP <ffff9708f861be00>
[1504481.048339] CR2: 0000000000000ce8

• another log:

[ 3166.838586] general protection fault: 0000 [#1] SMP
[ 3166.839935] Modules linked in: nfsv3 nfs fscache uinput snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq iosf_mbi crc32_pclmul snd_seq_device ghash_clmulni_intel aesni_intel snd_pcm snd_timer lrw snd ppdev soundcore gf128mul glue_helper ablk_helper joydev sg cryptd pcspkr virtio_balloon virtio_rng parport_pc i2c_piix4 parport nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sr_mod cdrom ata_generic pata_acpi virtio_blk virtio_console virtio_net qxl net_failover failover drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crct10dif_pclmul crct10dif_common ata_piix crc32c_intel libata serio_raw virtio_pci virtio_ring virtio drm_panel_orientation_quirks floppy dm_mirror dm_region_hash dm_log dm_mod
[ 3166.840861] CPU: 1 PID: 32558 Comm: umount.nfs Kdump: loaded Tainted: G        W      ------------   3.10.0-1127.el7.x86_64 #1
[ 3166.841073] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 3166.841180] task: ffff8c27985ea130 ti: ffff8c27b9b98000 task.ti: ffff8c27b9b98000
[ 3166.841288] RIP: 0010:[<ffffffffc04f9229>]  [<ffffffffc04f9229>] lockd_down_net+0x19/0xc0 [lockd]
[ 3166.841407] RSP: 0018:ffff8c27b9b9bdf8  EFLAGS: 00010202
[ 3166.841514] RAX: 0000000000000004 RBX: 6b6b6b6b6b6b6b6b RCX: ffff8c27b9b9bfd8
[ 3166.841623] RDX: 0000000000000000 RSI: 6b6b6b6b6b6b6b6b RDI: ffff8c27b9b6c908
[ 3166.841730] RBP: ffff8c27b9b9be10 R08: 000000000000000a R09: 0000000000000000
[ 3166.845517] R10: 0000000000000275 R11: ffff8c27b9b9babe R12: 6b6b6b6b6b6b6b6b
[ 3166.846274] R13: ffff8c27985ea130 R14: ffffffffa2106570 R15: ffff8c27985ea900
[ 3166.847026] FS:  00007f7fb09d0880(0000) GS:ffff8c27bfd00000(0000) knlGS:0000000000000000
[ 3166.847784] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3166.848534] CR2: 000000000f90c001 CR3: 00000000545e2000 CR4: 00000000001606e0
[ 3166.849285] Call Trace:
[ 3166.850021]  [<ffffffffc04f92ff>] lockd_down+0x2f/0xe0 [lockd]
[ 3166.850760]  [<ffffffffc04f50de>] nlmclnt_done+0x1e/0x30 [lockd]
[ 3166.851498]  [<ffffffffc0775767>] nfs_destroy_server+0x17/0x20 [nfs]
[ 3166.852225]  [<ffffffffc0776386>] nfs_free_server+0x36/0xd0 [nfs]
[ 3166.852972]  [<ffffffffc078316b>] nfs_kill_super+0x2b/0x30 [nfs]
[ 3166.853738]  [<ffffffffa12502ee>] deactivate_locked_super+0x4e/0x70
[ 3166.854566]  [<ffffffffa1250a76>] deactivate_super+0x46/0x60
[ 3166.855284]  [<ffffffffa126ffaf>] cleanup_mnt+0x3f/0x80
[ 3166.856057]  [<ffffffffa1270042>] __cleanup_mnt+0x12/0x20
[ 3166.856769]  [<ffffffffa10c31cb>] task_work_run+0xbb/0xe0
[ 3166.857479]  [<ffffffffa102cc65>] do_notify_resume+0xa5/0xc0
[ 3166.858179]  [<ffffffffa179322f>] int_signal+0x12/0x17
[ 3166.858860] Code: 93 05 00 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 8b 05 84 eb 00 00 48 89 e5 41 55 41 54 49 89 f4 53 85 c0 <48> 8b 8e e8 0c 00 00 74 75 3b 01 77 71 83 e8 01 48 98 48 8b 5c
[ 3166.860356] RIP  [<ffffffffc04f9229>] lockd_down_net+0x19/0xc0 [lockd]
[ 3166.861074]  RSP <ffff8c27b9b9bdf8>