==================================================================
BUG: KASAN: use-after-free in class_equal+0x40/0x50 kernel/locking/lockdep.c:1579
Read of size 8 at addr ffff88807ba94a80 by task syz-executor.1/9472

CPU: 0 PID: 9472 Comm: syz-executor.1 Not tainted 5.2.0-rc7-next-20190703 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:

The buggy address belongs to the page:
page:ffffea0001eea500 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 ffffea0001eea508 ffffea0001eea508 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88807ba94980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807ba94a00: ff ff ff ff ff ff f1 f1 f1 f1 00 f2 f2 f2 ff ff
>ffff88807ba94a80: ff ff 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 ff ff
                   ^
 ffff88807ba94b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807ba94b80: ff ff ff ff ff ff ff ff f1 f1 f1 f1 00 f3 f3 f3
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
Kernel Offset: disabled