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References: <20230210041030.865478-1-zyytlz.wz@163.com>
In-Reply-To: <20230210041030.865478-1-zyytlz.wz@163.com>
From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Fri, 10 Feb 2023 11:53:23 -0800
Message-ID: <CABBYNZL_gZ+kr_OEqjYgMmt+=91=jC88g310F-ScMC=kLh0xdw@mail.gmail.com>
Subject: Re: [PATCH] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor
To:     Zheng Wang <zyytlz.wz@163.com>
Cc:     marcel@holtmann.org, hackerzheng666@gmail.com,
        alex000young@gmail.com, johan.hedberg@gmail.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, linux-bluetooth@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Zheng,

On Thu, Feb 9, 2023 at 8:11 PM Zheng Wang <zyytlz.wz@163.com> wrote:
>
> In hci_remove_adv_monitor, if it gets into HCI_ADV_MONITOR_EXT_MSFT case,
> the function will free the monitor and print its handle after that.
>
> Fix it by switch the order.
>
> Fixes: 7cf5c2978f23 ("Bluetooth: hci_sync: Refactor remove Adv Monitor")
> Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
> ---
>  net/bluetooth/hci_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index b65c3aabcd53..db3352c60de6 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -1980,9 +1980,9 @@ static int hci_remove_adv_monitor(struct hci_dev *hdev,
>                 goto free_monitor;
>
>         case HCI_ADV_MONITOR_EXT_MSFT:
> -               status = msft_remove_monitor(hdev, monitor);
>                 bt_dev_dbg(hdev, "%s remove monitor %d msft status %d",
>                            hdev->name, monitor->handle, status);
> +               status = msft_remove_monitor(hdev, monitor);

I wonder if it is not a good idea to move the logging inside
msft_remove_monitor?

>                 break;
>         }
>
> --
> 2.25.1
>


-- 
Luiz Augusto von Dentz