2023-02-17 10:05:03

by Zheng Wang

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

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 <[email protected]>
---
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

2023-03-13 09:55:55

by Zheng Hacker

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

friendly ping

Zheng Wang <[email protected]> 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 <[email protected]>
> ---
> 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
>

2023-03-14 15:06:29

by Simon Horman

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

On Mon, Mar 13, 2023 at 05:55:35PM +0800, Zheng Hacker wrote:
> friendly ping
>
> Zheng Wang <[email protected]> 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 <[email protected]>
> > ---
> > 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
> >
>

2023-03-14 15:22:59

by Simon Horman

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

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 <[email protected]> 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 <[email protected]>
> > > ---
> > > 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
> > >
> >

2023-03-15 09:02:24

by Zheng Hacker

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

Simon Horman <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > > > ---
> > > > 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
> > > >
> > >