[PATCH v2] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor

[PATCH v2] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor

[Zheng Wang]

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 *hdev,
 
 	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);
 		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(struct 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 Monitor */
-- 
2.25.1

Re: [PATCH v2] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor

[Zheng Hacker]

friendly ping

Zheng Wang <zyytlz.wz@163.com> 于2023年2月17日周五 18:05写道：
>
> 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 *hdev,
>
>         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);
>                 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(struct 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 Monitor */
> --
> 2.25.1
>

Re: [PATCH v2] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor

[Simon Horman]

On Mon, Mar 13, 2023 at 05:55:35PM +0800, Zheng Hacker wrote:
> friendly ping
> 
> Zheng Wang <zyytlz.wz@163.com> 于2023年2月17日周五 18:05写道：
> >
> > 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 *hdev,
> >
> >         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);
> >                 break;

I'm probably missing something obvious.
But from my perspective a simpler fix would be to
move the msft_remove_monitor() call to below the bt_dev_dbg() call.

> >         }
> >
> > 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(struct 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 Monitor */
> > --
> > 2.25.1
> >
> 

Re: [PATCH v2] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor

[Simon Horman]

On Tue, Mar 14, 2023 at 04:06:11PM +0100, Simon Horman wrote:
> On Mon, Mar 13, 2023 at 05:55:35PM +0800, Zheng Hacker wrote:
> > friendly ping
> > 
> > Zheng Wang <zyytlz.wz@163.com> 于2023年2月17日周五 18:05写道：
> > >
> > > 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 *hdev,
> > >
> > >         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);
> > >                 break;
> 
> I'm probably missing something obvious.
> But from my perspective a simpler fix would be to
> move the msft_remove_monitor() call to below the bt_dev_dbg() call.

The obvious thing I was missing is that was what was done in v1
but Luiz suggested moving the logging to
msft_le_cancel_monitor_advertisement_cb().
Sorry for the noise.

Link: https://lore.kernel.org/all/CABBYNZL_gZ+kr_OEqjYgMmt+=91=jC88g310F-ScMC=kLh0xdw@mail.gmail.com/

> 
> > >         }
> > >
> > > 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(struct 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 Monitor */
> > > --
> > > 2.25.1
> > >
> > 

Re: [PATCH v2] Bluetooth: hci_core: Fix poential Use-after-Free bug in hci_remove_adv_monitor

[Zheng Hacker]

Simon Horman <simon.horman@corigine.com> 于2023年3月14日周二 23:22写道：
>
> On Tue, Mar 14, 2023 at 04:06:11PM +0100, Simon Horman wrote:
> > On Mon, Mar 13, 2023 at 05:55:35PM +0800, Zheng Hacker wrote:
> > > friendly ping
> > >
> > > Zheng Wang <zyytlz.wz@163.com> 于2023年2月17日周五 18:05写道：
> > > >
> > > > 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 *hdev,
> > > >
> > > >         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);
> > > >                 break;
> >
> > I'm probably missing something obvious.
> > But from my perspective a simpler fix would be to
> > move the msft_remove_monitor() call to below the bt_dev_dbg() call.
>
> The obvious thing I was missing is that was what was done in v1
> but Luiz suggested moving the logging to
> msft_le_cancel_monitor_advertisement_cb().
> Sorry for the noise.

Hi Simon,

Thanks for your reply and detailed review :)

Best regards,
Zheng

>
> Link: https://lore.kernel.org/all/CABBYNZL_gZ+kr_OEqjYgMmt+=91=jC88g310F-ScMC=kLh0xdw@mail.gmail.com/
>
> >
> > > >         }
> > > >
> > > > 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(struct 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 Monitor */
> > > > --
> > > > 2.25.1
> > > >
> > >