L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
REISERFS (device loop3): checking transaction log (loop3)
REISERFS (device loop3): Using rupasov hash to sort names
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 992b9067 P4D 992b9067 PUD 98be6067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9799 Comm: syz-executor.3 Not tainted 4.19.192-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:ffff888039c0f8a8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff11007381f18 RCX: ffffc9000c260000
RDX: 0000000000000000 RSI: ffff88808dc69b80 RDI: ffff888239b011a8
RBP: ffffffff8878d5c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88808dc69b80
R13: ffff888239b011a8 R14: ffff888039c0fa38 R15: ffff888039c0f8e0
FS:  00007f95a79f4700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000098d5a000 CR4: 00000000001426f0
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/0x2cf0 fs/reiserfs/super.c:2179
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x310 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: 0033:0x467afa
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f95a79f3fa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000467afa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f95a79f4000
RBP: 00007f95a79f4040 R08: 00007f95a79f4040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f95a79f4000 R15: 0000000020011500
Modules linked in:
CR2: 0000000000000000
---[ end trace 8d0b6e35e3a0d4b4 ]---
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff888039c0f8a8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff11007381f18 RCX: ffffc9000c260000
UDF-fs: error (device loop1): udf_process_sequence: Primary Volume Descriptor not found!
RDX: 0000000000000000 RSI: ffff88808dc69b80 RDI: ffff888239b011a8
audit: type=1804 audit(1622526527.664:3): pid=9808 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.4" name="/root/syzkaller-testdir485003026/syzkaller.WlsJr2/2/cgroup.controllers" dev="sda1" ino=13928 res=1
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'.
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2020/09/19 18:44 (1000)
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'.
RBP: ffffffff8878d5c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88808dc69b80
device batadv0 entered promiscuous mode
R13: ffff888239b011a8 R14: ffff888039c0fa38 R15: ffff888039c0f8e0
FS:  00007f95a79f4700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056179c7a6188 CR3: 0000000098d5a000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'.
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400