Re: [DMARC error] Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in skb_queue_purge_reason (2)

[Arseniy Krasnov]

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