ubuntu_aufs_smoke_test failed with kernel oops on X-hwe ARM64

Issue found on node wright-kernel

Fail rate: 3/4

Test failed with:
    aufs: simple stat check (access time): PASSED
    aufs: simple stat check (modify time): PASSED
    aufs: simple stat check (change size): PASSED
    aufs: umount: PASSED
    Segmentation fault
    aufs: mount/umount (repeated) FAILED

[ 93.162595] aufs 4.15-20180219
[ 126.920188] ------------[ cut here ]------------
[ 126.920199] kernel BUG at /build/linux-hwe-X0CTsn/linux-hwe-4.15.0/fs/buffer.c:1240!
[ 126.928084] Internal error: Oops - BUG: 0 [#1] SMP
[ 126.932931] Modules linked in: aufs nls_iso8859_1 thunderx_zip i2c_thunderx cavium_rng_vf thunderx_edac shpchp cavium_rng gpio_keys uio_pdrv_genirq uio ipmi_ssif ipmi_devintf ipmi_msghandler ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear ast i2c_algo_bit nicvf aes_ce_blk aes_ce_cipher ttm crc32_ce crct10dif_ce drm_kms_helper ghash_ce sha2_ce syscopyarea sysfillrect sysimgblt sha256_arm64 nicpf fb_sys_fops sha1_ce drm ahci thunder_bgx libahci thunder_xcv mdio_thunder thunderx_mmc mdio_cavium aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64
[ 126.999009] Process mount (pid: 6895, stack limit = 0x00000000386df78b)
[ 127.005702] CPU: 93 PID: 6895 Comm: mount Not tainted 4.15.0-73-generic #82~16.04.1-Ubuntu
[ 127.014058] Hardware name: Cavium ThunderX CRB/To be filled by O.E.M., BIOS 5.11 12/12/2012
[ 127.022503] pstate: 20400085 (nzCv daIf +PAN -UAO)
[ 127.027366] pc : __find_get_block+0x17c/0x328
[ 127.031771] lr : __getblk_gfp+0x44/0x2a0
[ 127.035734] sp : ffff00003a493480
[ 127.039081] x29: ffff00003a493480 x28: ffff800f9ebb2d00
[ 127.044453] x27: ffff800faf1d3800 x26: 0000000000000000
[ 127.049824] x25: 0000000000000000 x24: 0000000000000000
[ 127.055196] x23: 0000000000000008 x22: 000000000700202a
[ 127.060567] x21: ffff810fb995db00 x20: 000000000700202a
[ 127.065938] x19: 0000000000001000 x18: 0000000000000000
[ 127.071310] x17: 0000000000000000 x16: 0000000000000000
[ 127.076681] x15: ffffffffffffffff x14: ffffffffff000000
[ 127.082053] x13: ffffffffffffffff x12: 0000000000000038
[ 127.087424] x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f
[ 127.092795] x9 : 0000000000000000 x8 : 0000000000000008
[ 127.098166] x7 : ffff800f9f403080 x6 : ffff810fa9716600
[ 127.103538] x5 : 0000000000000000 x4 : 0000000000002020
[ 127.108909] x3 : 0000000000000008 x2 : 0000000000001000
[ 127.114281] x1 : 000000000700202a x0 : 0000000000000080
[ 127.119653] Call trace:
[ 127.124173] __find_get_block+0x17c/0x328
[ 127.130256] __getblk_gfp+0x44/0x2a0
[ 127.135901] ext4_getblk+0xd0/0x1c8
[ 127.141384] ext4_bread_batch+0x70/0x1a8
[ 127.147244] ext4_find_entry+0x2ec/0x550
[ 127.153074] ext4_lookup+0x8c/0x230
[ 127.158406] lookup_open+0x584/0x688
[ 127.163749] do_last+0x484/0x8b0
[ 127.168671] path_openat+0xa4/0x2e0
[ 127.173788] do_filp_open+0x84/0x108
[ 127.178932] file_open_name+0x12c/0x168
[ 127.184265] filp_open+0x44/0x80
[ 127.189029] vfsub_filp_open+0x34/0x60 [aufs]
[ 127.194776] au_xino_create+0x40/0x260 [aufs]
[ 127.200480] au_xino_def+0x174/0x2e8 [aufs]
[ 127.205954] au_opts_mount+0x1d8/0x250 [aufs]
[ 127.211555] aufs_fill_super+0x1b4/0x350 [aufs]
[ 127.217268] mount_nodev+0x5c/0xd0
[ 127.221853] aufs_mount+0x40/0x100 [aufs]
[ 127.227031] mount_fs+0x54/0x180
[ 127.231426] vfs_kern_mount+0x58/0x130
[ 127.236344] do_mount+0x1d8/0xc08
[ 127.240818] SyS_mount+0xa8/0x100
[ 127.245299] el0_svc_naked+0x30/0x34
[ 127.250051] Code: d63f0040 f8418e82 b5ffff82 17ffffde (d4210000)
[ 127.257385] ---[ end trace 470c38625d11b576 ]---

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.15.0-73-generic 4.15.0-73.82~16.04.1
ProcVersionSignature: User Name 4.15.0-73.82~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-73-generic aarch64
ApportVersion: 2.20.1-0ubuntu2.21
Architecture: arm64
Date: Mon Dec 9 02:28:12 2019
SourcePackage: linux-hwe
UpgradeStatus: No upgrade log present (probably fresh install)