syzbot suspects this issue was fixed by commit:

commit dfd402a4c4baae42398ce9180ff424d589b8bffc
Author: Marco Elver [off-list ref]
Date:   Thu Nov 14 18:02:54 2019 +0000

    kcsan: Add Kernel Concurrency Sanitizer infrastructure

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=13eb65d6900000
start commit:   46cf053e Linux 5.5-rc3
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=ed9d672709340e35
dashboard link: https://syzkaller.appspot.com/bug?extid=02d9172bf4c43104cd70
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=147e5ac1e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14b49e71e00000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: kcsan: Add Kernel Concurrency Sanitizer infrastructure

For information about bisection process see: https://goo.gl/tpsmEJ#bisection