* [PATCH v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race
@ 2024-05-13 2:19 Sicong Huang
2024-06-04 13:11 ` Greg KH
0 siblings, 1 reply; 4+ messages in thread
From: Sicong Huang @ 2024-05-13 2:19 UTC (permalink / raw)
To: peter.chen, pawell, rogerq, gregkh; +Cc: linux-usb, Sicong Huang
This bug exists in drivers/usb/cdns3/cdns3-gadget.c. Function
__cdns3_gadget_init will call cdns3_gadget_start to do futher jobs
during the initialization proccess of cdns3 gadget. In cdns3_gadget_start,
&priv_dev->pending_status_wq is bound with cdns3_pending_setup_status_handler.
Then this work will be added to system_freezable_wq in cdns3_gadget_ep0_queue.
Here is the code.
queue_work(system_freezable_wq, &priv_dev->pending_status_wq);
If we call cdns3_gadget_exit to remove the device and make cleanup,
there are some unfinished works. This function will call cdns3_free_all_eps to
free all the endpoints. However, if cdns3_pending_setup_status_handler is
scheduled to run after the free job, it will cause use-after-free error as
cdns3_pending_setup_status_handler will use the endpoint in the following code.
request->complete(&priv_dev->eps[0]->endpoint, request);
The possible execution flow that may lead to this issue is as follows:
CPU0 CPU1
| __cdns3_gadget_init
| cdns3_gadget_start
cdns3_gadget_exit |
cdns3_free_all_eps |
devm_kfree (free) |
| cdns3_pending_setup_status_handler
| &priv_dev->eps[0]->endpoint (use)
Fix it by cleaning the work in cdns3_gadget_exit.
Signed-off-by: Sicong Huang <congei42@163.com>
---
drivers/usb/cdns3/cdns3-gadget.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index fd1beb10bba7..0f2e143bd17a 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -3252,6 +3252,9 @@ static void cdns3_gadget_exit(struct cdns *cdns)
pm_runtime_mark_last_busy(cdns->dev);
pm_runtime_put_autosuspend(cdns->dev);
+ cancel_work_sync(&priv_dev->pending_status_wq);
+ cancel_work_sync(&priv_dev->aligned_buf_wq);
+
usb_del_gadget(&priv_dev->gadget);
devm_free_irq(cdns->dev, cdns->dev_irq, priv_dev);
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race
2024-05-13 2:19 [PATCH v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race Sicong Huang
@ 2024-06-04 13:11 ` Greg KH
2024-06-05 2:36 ` sicong
0 siblings, 1 reply; 4+ messages in thread
From: Greg KH @ 2024-06-04 13:11 UTC (permalink / raw)
To: Sicong Huang; +Cc: peter.chen, pawell, rogerq, linux-usb
On Mon, May 13, 2024 at 10:19:48AM +0800, Sicong Huang wrote:
> This bug exists in drivers/usb/cdns3/cdns3-gadget.c. Function
> __cdns3_gadget_init will call cdns3_gadget_start to do futher jobs
> during the initialization proccess of cdns3 gadget. In cdns3_gadget_start,
> &priv_dev->pending_status_wq is bound with cdns3_pending_setup_status_handler.
> Then this work will be added to system_freezable_wq in cdns3_gadget_ep0_queue.
> Here is the code.
> queue_work(system_freezable_wq, &priv_dev->pending_status_wq);
>
> If we call cdns3_gadget_exit to remove the device and make cleanup,
> there are some unfinished works. This function will call cdns3_free_all_eps to
> free all the endpoints. However, if cdns3_pending_setup_status_handler is
> scheduled to run after the free job, it will cause use-after-free error as
> cdns3_pending_setup_status_handler will use the endpoint in the following code.
> request->complete(&priv_dev->eps[0]->endpoint, request);
>
> The possible execution flow that may lead to this issue is as follows:
> CPU0 CPU1
> | __cdns3_gadget_init
> | cdns3_gadget_start
> cdns3_gadget_exit |
> cdns3_free_all_eps |
> devm_kfree (free) |
> | cdns3_pending_setup_status_handler
> | &priv_dev->eps[0]->endpoint (use)
>
> Fix it by cleaning the work in cdns3_gadget_exit.
>
> Signed-off-by: Sicong Huang <congei42@163.com>
> ---
> drivers/usb/cdns3/cdns3-gadget.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index fd1beb10bba7..0f2e143bd17a 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -3252,6 +3252,9 @@ static void cdns3_gadget_exit(struct cdns *cdns)
> pm_runtime_mark_last_busy(cdns->dev);
> pm_runtime_put_autosuspend(cdns->dev);
>
> + cancel_work_sync(&priv_dev->pending_status_wq);
> + cancel_work_sync(&priv_dev->aligned_buf_wq);
> +
> usb_del_gadget(&priv_dev->gadget);
> devm_free_irq(cdns->dev, cdns->dev_irq, priv_dev);
>
> --
> 2.34.1
What commit id does this fix?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re:Re: [PATCH v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race
2024-06-04 13:11 ` Greg KH
@ 2024-06-05 2:36 ` sicong
2024-06-05 8:41 ` Greg KH
0 siblings, 1 reply; 4+ messages in thread
From: sicong @ 2024-06-05 2:36 UTC (permalink / raw)
To: Greg KH; +Cc: peter.chen, pawell, rogerq, linux-usb
At 2024-06-04 21:11:57, "Greg KH" <gregkh@linuxfoundation.org> wrote:
>On Mon, May 13, 2024 at 10:19:48AM +0800, Sicong Huang wrote:
>> This bug exists in drivers/usb/cdns3/cdns3-gadget.c. Function
>> __cdns3_gadget_init will call cdns3_gadget_start to do futher jobs
>> during the initialization proccess of cdns3 gadget. In cdns3_gadget_start,
>> &priv_dev->pending_status_wq is bound with cdns3_pending_setup_status_handler.
>> Then this work will be added to system_freezable_wq in cdns3_gadget_ep0_queue.
>> Here is the code.
>> queue_work(system_freezable_wq, &priv_dev->pending_status_wq);
>>
>> If we call cdns3_gadget_exit to remove the device and make cleanup,
>> there are some unfinished works. This function will call cdns3_free_all_eps to
>> free all the endpoints. However, if cdns3_pending_setup_status_handler is
>> scheduled to run after the free job, it will cause use-after-free error as
>> cdns3_pending_setup_status_handler will use the endpoint in the following code.
>> request->complete(&priv_dev->eps[0]->endpoint, request);
>>
>> The possible execution flow that may lead to this issue is as follows:
>> CPU0 CPU1
>> | __cdns3_gadget_init
>> | cdns3_gadget_start
>> cdns3_gadget_exit |
>> cdns3_free_all_eps |
>> devm_kfree (free) |
>> | cdns3_pending_setup_status_handler
>> | &priv_dev->eps[0]->endpoint (use)
>>
>> Fix it by cleaning the work in cdns3_gadget_exit.
>>
>> Signed-off-by: Sicong Huang <congei42@163.com>
>> ---
>> drivers/usb/cdns3/cdns3-gadget.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
>> index fd1beb10bba7..0f2e143bd17a 100644
>> --- a/drivers/usb/cdns3/cdns3-gadget.c
>> +++ b/drivers/usb/cdns3/cdns3-gadget.c
>> @@ -3252,6 +3252,9 @@ static void cdns3_gadget_exit(struct cdns *cdns)
>> pm_runtime_mark_last_busy(cdns->dev);
>> pm_runtime_put_autosuspend(cdns->dev);
>>
>> + cancel_work_sync(&priv_dev->pending_status_wq);
>> + cancel_work_sync(&priv_dev->aligned_buf_wq);
>> +
>> usb_del_gadget(&priv_dev->gadget);
>> devm_free_irq(cdns->dev, cdns->dev_irq, priv_dev);
>>
>> --
>> 2.34.1
>
>What commit id does this fix?
>
>thanks,
>
>greg k-h
I made the changes based on the following commit information.
commit 51474ab44abf907023a8a875e799b07de461e466 (origin/usb-testing, origin/usb-next)
regards,
Sicong Huang
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Re: [PATCH v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race
2024-06-05 2:36 ` sicong
@ 2024-06-05 8:41 ` Greg KH
0 siblings, 0 replies; 4+ messages in thread
From: Greg KH @ 2024-06-05 8:41 UTC (permalink / raw)
To: sicong; +Cc: peter.chen, pawell, rogerq, linux-usb
On Wed, Jun 05, 2024 at 10:36:30AM +0800, sicong wrote:
>
>
> At 2024-06-04 21:11:57, "Greg KH" <gregkh@linuxfoundation.org> wrote:
> >On Mon, May 13, 2024 at 10:19:48AM +0800, Sicong Huang wrote:
> >> This bug exists in drivers/usb/cdns3/cdns3-gadget.c. Function
> >> __cdns3_gadget_init will call cdns3_gadget_start to do futher jobs
> >> during the initialization proccess of cdns3 gadget. In cdns3_gadget_start,
> >> &priv_dev->pending_status_wq is bound with cdns3_pending_setup_status_handler.
> >> Then this work will be added to system_freezable_wq in cdns3_gadget_ep0_queue.
> >> Here is the code.
> >> queue_work(system_freezable_wq, &priv_dev->pending_status_wq);
> >>
> >> If we call cdns3_gadget_exit to remove the device and make cleanup,
> >> there are some unfinished works. This function will call cdns3_free_all_eps to
> >> free all the endpoints. However, if cdns3_pending_setup_status_handler is
> >> scheduled to run after the free job, it will cause use-after-free error as
> >> cdns3_pending_setup_status_handler will use the endpoint in the following code.
> >> request->complete(&priv_dev->eps[0]->endpoint, request);
> >>
> >> The possible execution flow that may lead to this issue is as follows:
> >> CPU0 CPU1
> >> | __cdns3_gadget_init
> >> | cdns3_gadget_start
> >> cdns3_gadget_exit |
> >> cdns3_free_all_eps |
> >> devm_kfree (free) |
> >> | cdns3_pending_setup_status_handler
> >> | &priv_dev->eps[0]->endpoint (use)
> >>
> >> Fix it by cleaning the work in cdns3_gadget_exit.
> >>
> >> Signed-off-by: Sicong Huang <congei42@163.com>
> >> ---
> >> drivers/usb/cdns3/cdns3-gadget.c | 3 +++
> >> 1 file changed, 3 insertions(+)
> >>
> >> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> >> index fd1beb10bba7..0f2e143bd17a 100644
> >> --- a/drivers/usb/cdns3/cdns3-gadget.c
> >> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> >> @@ -3252,6 +3252,9 @@ static void cdns3_gadget_exit(struct cdns *cdns)
> >> pm_runtime_mark_last_busy(cdns->dev);
> >> pm_runtime_put_autosuspend(cdns->dev);
> >>
> >> + cancel_work_sync(&priv_dev->pending_status_wq);
> >> + cancel_work_sync(&priv_dev->aligned_buf_wq);
> >> +
> >> usb_del_gadget(&priv_dev->gadget);
> >> devm_free_irq(cdns->dev, cdns->dev_irq, priv_dev);
> >>
> >> --
> >> 2.34.1
> >
> >What commit id does this fix?
> >
> >thanks,
> >
>
> >greg k-h
>
>
> I made the changes based on the following commit information.
> commit 51474ab44abf907023a8a875e799b07de461e466 (origin/usb-testing, origin/usb-next)
That is not what I meant, sorry.
I mean, "this is a bugfix, so what commit caused the problem that this
is fixing?"
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-05-13 2:19 [PATCH v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race Sicong Huang
2024-06-04 13:11 ` Greg KH
2024-06-05 2:36 ` sicong
2024-06-05 8:41 ` Greg KH
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