syzbot has bisected this bug to:

commit 8f840e47f190cbe61a96945c13e9551048d42cef
Author: Xin Long [off-list ref]
Date:   Thu Apr 14 07:35:33 2016 +0000

     sctp: add the sctp_diag.c file

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1719585b200000
start commit:   0072a0c1 Merge tag 'media/v4.20-4' of git://git.kernel.org..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=1499585b200000
console output: https://syzkaller.appspot.com/x/log.txt?x=1099585b200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b9cc5a440391cbfd
dashboard link: https://syzkaller.appspot.com/bug?extid=9276d76e83e3bcde6c99
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12b80cfb400000

Reported-by: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com
Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file")

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