Hi, I guess problem here is that, if hci_uart_tty_close() will be called between setting HCI_UART_PROTO_READY and skb_queue_head_init(), in that case mrvl_close() will access uninitialized data. hci_uart_set_proto() { ... set_bit(HCI_UART_PROTO_READY, &hu->flags); err = hci_uart_register_dev(hu); mrvl_open() skb_queue_head_init(); if (err) { return err; } ... } Thanks On 10.02.2025 14:26, syzbot wrote: > syzbot has bisected this issue to: > > commit c411c62cc13319533b1861e00cedc4883c3bc1bb > Author: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx> > Date: Thu Jan 30 18:43:26 2025 +0000 > > Bluetooth: hci_uart: fix race during initialization > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=116cebdf980000 > start commit: 40b8e93e17bf Add linux-next specific files for 20250204 > git tree: linux-next > final oops: https://syzkaller.appspot.com/x/report.txt?x=136cebdf980000 > console output: https://syzkaller.appspot.com/x/log.txt?x=156cebdf980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ec880188a87c6aad > dashboard link: https://syzkaller.appspot.com/bug?extid=683f8cb11b94b1824c77 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b7eeb0580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12f74f64580000 > > Reported-by: syzbot+683f8cb11b94b1824c77@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: c411c62cc133 ("Bluetooth: hci_uart: fix race during initialization") > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection