==================================================================
BUG: KASAN: use-after-free in class_equal+0x40/0x50 kernel/locking/lockdep.c:1579
Read of size 8 at addr ffff88807b966f70 by task syz-executor.5/9518

CPU: 1 PID: 9518 Comm: syz-executor.5 Not tainted 5.2.0-next-20190710 #35
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:

The buggy address belongs to the page:
page:ffffea0001ee5980 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 0000000000000000 ffffea0001ee5988 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88807b966e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807b966e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88807b966f00: ff ff ff ff f1 f1 f1 f1 00 f2 f2 f2 ff ff ff ff
                                                             ^
 ffff88807b966f80: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 ff ff ff ff
 ffff88807b967000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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Kernel panic - not syncing: panic_on_warn set ...
Kernel Offset: disabled