syzbot suspects this bug was fixed by commit: commit b36a1552d7319bbfd5cf7f08726c23c5c66d4f73 Author: Vladis Dronov <vdronov@xxxxxxxxxx> Date: Tue Jul 30 09:33:45 2019 +0000 Bluetooth: hci_uart: check for missing tty operations bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10b20aeae00000 start commit: 66c56cfa Merge tag 'remove-dma_zalloc_coherent-5.0' of git.. git tree: upstream kernel config: https://syzkaller.appspot.com/x/.config?x=b05cfdb4ee8ab9b2 dashboard link: https://syzkaller.appspot.com/bug?extid=a950165cbb86bdd023a4 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=121cee07400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fdaed8c00000 If the result looks correct, please mark the bug fixed by replying with: #syz fix: Bluetooth: hci_uart: check for missing tty operations For information about bisection process see: https://goo.gl/tpsmEJ#bisection