ufs: You didn't specify the type of your ufs filesystem
mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
>>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
REISERFS (device loop4): Using rupasov hash to sort names
REISERFS (device loop4): using 3.5.x disk format
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD afcb6067 P4D afcb6067 PUD 9db6b067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 11624 Comm: syz-executor.4 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff8880592478a8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff1100b248f18 RCX: ffffc9000e467000
RDX: 0000000000000000 RSI: ffff88808d87eca0 RDI: ffff88804b0aa740
RBP: ffffffff8878cf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88808d87eca0
R13: ffff88804b0aa740 R14: ffff888059247a38 R15: ffff8880592478e0
FS:  00007f395affa700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000009dadb000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __lookup_slow+0x246/0x4a0 fs/namei.c:1672
 lookup_one_len+0x163/0x190 fs/namei.c:2544
 reiserfs_lookup_privroot+0x92/0x280 fs/reiserfs/xattr.c:970
 reiserfs_fill_super+0x202c/0x2ce4 fs/reiserfs/super.c:2179
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x113c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x46090a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f395aff9a88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f395aff9b20 RCX: 000000000046090a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f395aff9ae0
RBP: 00007f395aff9ae0 R08: 00007f395aff9b20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020011100
Modules linked in:
CR2: 0000000000000000
---[ end trace 1cbb9d80cd6644b1 ]---
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff8880592478a8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff1100b248f18 RCX: ffffc9000e467000
RDX: 0000000000000000 RSI: ffff88808d87eca0 RDI: ffff88804b0aa740
RBP: ffffffff8878cf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88808d87eca0
R13: ffff88804b0aa740 R14: ffff888059247a38 R15: ffff8880592478e0
FS:  00007f395affa700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000009dadb000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400