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References: <20230217100223.702330-1-zyytlz.wz@163.com>
In-Reply-To: <20230217100223.702330-1-zyytlz.wz@163.com>
From:   Zheng Hacker <hackerzheng666@gmail.com>
Date:   Mon, 13 Mar 2023 17:55:35 +0800
Message-ID: <CAJedcCxUNBWOpkcaN2aLbwNs_xvqi=LC8mhFWh-jWeh6q-cBCQ@mail.gmail.com>
Subject: Re: [PATCH v2] 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, alex000young@gmail.com,
        johan.hedberg@gmail.com, luiz.dentz@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, pmenzel@molgen.mpg.de
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friendly ping

Zheng Wang <zyytlz.wz@163.com> =E4=BA=8E2023=E5=B9=B42=E6=9C=8817=E6=97=A5=
=E5=91=A8=E4=BA=94 18:05=E5=86=99=E9=81=93=EF=BC=9A
>
> 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 removing the logging into msft_le_cancel_monitor_advertisement_=
cb
> before calling hci_free_adv_monitor.
>
> Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
> ---
> v2:
> - move the logging inside msft_remove_monitor suggested by Luiz
> ---
>  net/bluetooth/hci_core.c | 2 --
>  net/bluetooth/msft.c     | 2 ++
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index b65c3aabcd53..69b82c2907ff 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -1981,8 +1981,6 @@ static int hci_remove_adv_monitor(struct hci_dev *h=
dev,
>
>         case HCI_ADV_MONITOR_EXT_MSFT:
>                 status =3D msft_remove_monitor(hdev, monitor);
> -               bt_dev_dbg(hdev, "%s remove monitor %d msft status %d",
> -                          hdev->name, monitor->handle, status);
>                 break;
>         }
>
> diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
> index bee6a4c656be..4b35f0ed1360 100644
> --- a/net/bluetooth/msft.c
> +++ b/net/bluetooth/msft.c
> @@ -286,6 +286,8 @@ static int msft_le_cancel_monitor_advertisement_cb(st=
ruct hci_dev *hdev,
>                  * suspend. It will be re-monitored on resume.
>                  */
>                 if (!msft->suspending) {
> +                       bt_dev_dbg(hdev, "%s remove monitor %d status %d"=
, hdev->name,
> +                                  monitor->handle, status);
>                         hci_free_adv_monitor(hdev, monitor);
>
>                         /* Clear any monitored devices by this Adv Monito=
r */
> --
> 2.25.1
>