kernel panic occurred due to NULL pointer dereference in vnlayer_linux_new_clrvnode() function

Issue

• Kernel panics with following stack traces:

[   13.404423] dm-0: WRITE SAME failed. Manually zeroing.
[   13.850987] virbr0: port 1(virbr0-nic) entered disabled state
[   30.590947] fuse init (API version 7.22)
[   67.949034] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[   67.949039] IP: [<ffffffffa04a1f58>] vnlayer_linux_new_clrvnode+0x15/0x2e3 [mvfs]
[   67.949055] PGD d4dc067 PUD da4e067 PMD 0 
[   67.949057] Oops: 0000 [#1] SMP 
[   67.949059] Modules linked in: fuse xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6_tables iptable_filter rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache mvfs(OE) vfat fat intel_powerclamp coretemp crc32_pclmul ghash_clmulni_intel ppdev aesni_intel lrw gf128mul glue_helper ablk_helper cryptd vmw_balloon pcspkr sg i2c_piix4 vmw_vmci parport_pc shpchp parport nfsd nfs_acl lockd grace binfmt_misc auth_rpcgss sunrpc ip_tables ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif crct10dif_generic ata_generic pata_acpi crct10dif_pclmul crct10dif_common crc32c_intel vmwgfx serio_raw drm_kms_helper syscopyarea sysfillrect sysimgblt
[   67.949087]  fb_sys_fops ttm vmxnet3 vmw_pvscsi drm ata_piix i2c_core libata floppy fjes dm_mirror dm_region_hash dm_log dm_mod
[   67.949093] CPU: 0 PID: 4195 Comm: ls Tainted: G           OE  ------------   3.10.0-514.26.2.el7.x86_64 #1
[   67.949095] Hardware name: VMware, Inc. VMware7,1/440BX Desktop Reference Platform, BIOS VMW71.00V.0.B64.1607292324 07/29/2016
[   67.949096] task: ffff8802bf732f10 ti: ffff8800b4c0c000 task.ti: ffff8800b4c0c000
[   67.949097] RIP: 0010:[<ffffffffa04a1f58>]  [<ffffffffa04a1f58>] vnlayer_linux_new_clrvnode+0x15/0x2e3 [mvfs]
[   67.949106] RSP: 0018:ffff8800b4c0fa88  EFLAGS: 00010246
[   67.949107] RAX: ffffffff81a58a80 RBX: 0000000000000000 RCX: 0000000000000002
[   67.949108] RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffff88029887b300
[   67.949109] RBP: ffff8800b4c0fab0 R08: ffff88029887b210 R09: 000000000000006e
[   67.949110] R10: ffff8802bfc19a40 R11: ffffea000035a240 R12: 0000000000000000
[   67.949110] R13: ffff88029887b300 R14: ffff8802943e0f00 R15: 0000000000000000
[   67.949112] FS:  00007f8f9021f800(0000) GS:ffff8802bfc00000(0000) knlGS:0000000000000000
[   67.949113] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   67.949114] CR2: 0000000000000008 CR3: 000000000da4c000 CR4: 00000000001407f0
[   67.949154] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   67.949168] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   67.949169] Stack:
[   67.949170]  0000000000000000 ffff8800b4c0fb30 ffff88029887b300 ffff8802943e0f00
[   67.949171]  0000000000000000 ffff8800b4c0fae8 ffffffffa049e8ec ffff8800b4c0fbf8
[   67.949173]  ffff88029887b1b8 ffff8800b4c0fc18 ffff8800bb3b0000 ffff8802abee2800
[   67.949175] Call Trace:
[   67.949186]  [<ffffffffa049e8ec>] mvop_linux_lookup_component+0x16a/0x1c7 [mvfs]
[   67.949193]  [<ffffffffa045a5a6>] mvfs_lookup_ctx+0x42c/0xd92 [mvfs]
[   67.949203]  [<ffffffffa04942ae>] mvfs_linux_lookup_wrapper+0x11f/0x140 [mvfs]
[   67.949212]  [<ffffffffa049c5c7>] vnode_iop_lookup+0xb1/0x4c5 [mvfs]
[   67.949216]  [<ffffffff81208cad>] lookup_real+0x1d/0x50
[   67.949218]  [<ffffffff81209622>] __lookup_hash+0x42/0x60
[   67.949221]  [<ffffffff81684312>] lookup_slow+0x42/0xa7
[   67.949223]  [<ffffffff8120cb43>] path_lookupat+0x773/0x7a0
[   67.949231]  [<ffffffffa049bb2a>] ? vnlayer_xattr_getdent.isra.1+0x36/0x58 [mvfs]
[   67.949233]  [<ffffffff81208c37>] ? path_get+0x27/0x30
[   67.949235]  [<ffffffff8120cb9b>] filename_lookup+0x2b/0xc0
[   67.949236]  [<ffffffff812105b7>] user_path_at_empty+0x67/0xc0
[   67.949238]  [<ffffffff8121aa16>] ? evict+0x106/0x170
[   67.949240]  [<ffffffff8121b255>] ? iput+0xf5/0x180
[   67.949248]  [<ffffffffa04a4578>] ? mdki_vn_rele+0x12/0x14 [mvfs]
[   67.949255]  [<ffffffffa049fc2b>] ? vnlayer_dent_cvn_rele.isra.3+0x47/0x5c [mvfs]
[   67.949257]  [<ffffffff81210621>] user_path_at+0x11/0x20
[   67.949259]  [<ffffffff81203a93>] vfs_fstatat+0x63/0xc0
[   67.949261]  [<ffffffff81204061>] SYSC_newlstat+0x31/0x60
[   67.949263]  [<ffffffff8121f0ae>] ? mntput_no_expire+0x3e/0x120
[   67.949265]  [<ffffffff812042ee>] SyS_newlstat+0xe/0x10
[   67.949267]  [<ffffffff81697709>] system_call_fastpath+0x16/0x1b
[   67.949268] Code: 00 00 55 48 c7 c7 d2 a2 4b a0 31 c0 48 89 e5 e8 3c e6 1d e1 0f 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 f4 53 <48> 8b 46 08 48 89 fb 48 81 78 28 40 ad 4c a0 75 7e 48 8b b8 50 
[   67.949284] RIP  [<ffffffffa04a1f58>] vnlayer_linux_new_clrvnode+0x15/0x2e3 [mvfs]
[   67.949291]  RSP <ffff8800b4c0fa88>
[   67.949292] CR2: 0000000000000008