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* [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure
@ 2020-03-26  6:00 Sriharsha Allenki
  2020-03-26  8:16 ` Greg KH
  2020-03-26 11:19 ` Peter Chen
  0 siblings, 2 replies; 6+ messages in thread
From: Sriharsha Allenki @ 2020-03-26  6:00 UTC (permalink / raw)
  To: balbi, gregkh, linux-usb; +Cc: mgautam, jackp, Sriharsha Allenki

In AIO case, the request is freed up if ep_queue fails.
However, io_data->req still has the reference to this freed
request. In the case of this failure if there is aio_cancel
call on this io_data it will lead to an invalid dequeue
operation and a potential use after free issue.
Fix this by setting the io_data->req to NULL when the request
is freed as part of queue failure.

Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>
---
 drivers/usb/gadget/function/f_fs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 571917677d35..767f30b86645 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1120,6 +1120,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
 
 		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 		if (unlikely(ret)) {
+			io_data->req = NULL;
 			usb_ep_free_request(ep->ep, req);
 			goto error_lock;
 		}
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure
  2020-03-26  6:00 [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure Sriharsha Allenki
@ 2020-03-26  8:16 ` Greg KH
  2020-03-26  8:44   ` Sriharsha Allenki
  2020-03-26 11:19 ` Peter Chen
  1 sibling, 1 reply; 6+ messages in thread
From: Greg KH @ 2020-03-26  8:16 UTC (permalink / raw)
  To: Sriharsha Allenki; +Cc: balbi, linux-usb, mgautam, jackp

On Thu, Mar 26, 2020 at 11:30:33AM +0530, Sriharsha Allenki wrote:
> In AIO case, the request is freed up if ep_queue fails.
> However, io_data->req still has the reference to this freed
> request. In the case of this failure if there is aio_cancel
> call on this io_data it will lead to an invalid dequeue
> operation and a potential use after free issue.
> Fix this by setting the io_data->req to NULL when the request
> is freed as part of queue failure.
> 
> Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>
> ---
>  drivers/usb/gadget/function/f_fs.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> index 571917677d35..767f30b86645 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -1120,6 +1120,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
>  
>  		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
>  		if (unlikely(ret)) {
> +			io_data->req = NULL;
>  			usb_ep_free_request(ep->ep, req);
>  			goto error_lock;
>  		}
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project

What commit does this fix?  Should it go to stable kernels, and if so,
how far back?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure
  2020-03-26  8:16 ` Greg KH
@ 2020-03-26  8:44   ` Sriharsha Allenki
  2020-03-26  9:30     ` Greg KH
  0 siblings, 1 reply; 6+ messages in thread
From: Sriharsha Allenki @ 2020-03-26  8:44 UTC (permalink / raw)
  To: Greg KH; +Cc: balbi, linux-usb, mgautam, jackp

Hi Greg,

On 3/26/2020 1:46 PM, Greg KH wrote:
> On Thu, Mar 26, 2020 at 11:30:33AM +0530, Sriharsha Allenki wrote:
>> In AIO case, the request is freed up if ep_queue fails.
>> However, io_data->req still has the reference to this freed
>> request. In the case of this failure if there is aio_cancel
>> call on this io_data it will lead to an invalid dequeue
>> operation and a potential use after free issue.
>> Fix this by setting the io_data->req to NULL when the request
>> is freed as part of queue failure.
>>
>> Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>
>> ---
>>  drivers/usb/gadget/function/f_fs.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
>> index 571917677d35..767f30b86645 100644
>> --- a/drivers/usb/gadget/function/f_fs.c
>> +++ b/drivers/usb/gadget/function/f_fs.c
>> @@ -1120,6 +1120,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
>>  
>>  		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
>>  		if (unlikely(ret)) {
>> +			io_data->req = NULL;
>>  			usb_ep_free_request(ep->ep, req);
>>  			goto error_lock;
>>  		}
>> -- 
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
> What commit does this fix?  Should it go to stable kernels, and if so,
> how far back?
The commit 2e4c7553cd6f ("usb: gadget: f_fs: add aio support") introduced
the problem. It is good to have in stable kernels and it needs to go all
theway back to linux-3.15.y.

Hope this information helps.
>
> thanks,
>
> greg k-h
Regards,
Sriharsha

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure
  2020-03-26  8:44   ` Sriharsha Allenki
@ 2020-03-26  9:30     ` Greg KH
  2020-03-26 12:33       ` Sriharsha Allenki
  0 siblings, 1 reply; 6+ messages in thread
From: Greg KH @ 2020-03-26  9:30 UTC (permalink / raw)
  To: Sriharsha Allenki; +Cc: balbi, linux-usb, mgautam, jackp

On Thu, Mar 26, 2020 at 02:14:23PM +0530, Sriharsha Allenki wrote:
> Hi Greg,
> 
> On 3/26/2020 1:46 PM, Greg KH wrote:
> > On Thu, Mar 26, 2020 at 11:30:33AM +0530, Sriharsha Allenki wrote:
> >> In AIO case, the request is freed up if ep_queue fails.
> >> However, io_data->req still has the reference to this freed
> >> request. In the case of this failure if there is aio_cancel
> >> call on this io_data it will lead to an invalid dequeue
> >> operation and a potential use after free issue.
> >> Fix this by setting the io_data->req to NULL when the request
> >> is freed as part of queue failure.
> >>
> >> Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>
> >> ---
> >>  drivers/usb/gadget/function/f_fs.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> >> index 571917677d35..767f30b86645 100644
> >> --- a/drivers/usb/gadget/function/f_fs.c
> >> +++ b/drivers/usb/gadget/function/f_fs.c
> >> @@ -1120,6 +1120,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
> >>  
> >>  		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
> >>  		if (unlikely(ret)) {
> >> +			io_data->req = NULL;
> >>  			usb_ep_free_request(ep->ep, req);
> >>  			goto error_lock;
> >>  		}
> >> -- 
> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
> > What commit does this fix?  Should it go to stable kernels, and if so,
> > how far back?
> The commit 2e4c7553cd6f ("usb: gadget: f_fs: add aio support") introduced
> the problem. It is good to have in stable kernels and it needs to go all
> theway back to linux-3.15.y.
> 
> Hope this information helps.

Great, please resend this with the proper Fixes: and cc: stable... tag
on it so that it gets picked up properly.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure
  2020-03-26  6:00 [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure Sriharsha Allenki
  2020-03-26  8:16 ` Greg KH
@ 2020-03-26 11:19 ` Peter Chen
  1 sibling, 0 replies; 6+ messages in thread
From: Peter Chen @ 2020-03-26 11:19 UTC (permalink / raw)
  To: Sriharsha Allenki; +Cc: balbi, gregkh, linux-usb, mgautam, jackp

On 20-03-26 11:30:33, Sriharsha Allenki wrote:
> In AIO case, the request is freed up if ep_queue fails.
> However, io_data->req still has the reference to this freed
> request. In the case of this failure if there is aio_cancel
> call on this io_data it will lead to an invalid dequeue
> operation and a potential use after free issue.
> Fix this by setting the io_data->req to NULL when the request
> is freed as part of queue failure.
> 
> Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>

Reviewed-by: Peter Chen <peter.chen@nxp.com>

Peter
> ---
>  drivers/usb/gadget/function/f_fs.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> index 571917677d35..767f30b86645 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -1120,6 +1120,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
>  
>  		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
>  		if (unlikely(ret)) {
> +			io_data->req = NULL;
>  			usb_ep_free_request(ep->ep, req);
>  			goto error_lock;
>  		}
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project

-- 

Thanks,
Peter Chen

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure
  2020-03-26  9:30     ` Greg KH
@ 2020-03-26 12:33       ` Sriharsha Allenki
  0 siblings, 0 replies; 6+ messages in thread
From: Sriharsha Allenki @ 2020-03-26 12:33 UTC (permalink / raw)
  To: Greg KH; +Cc: balbi, linux-usb, mgautam, jackp

Hi Greg,
On 3/26/2020 3:00 PM, Greg KH wrote:
> On Thu, Mar 26, 2020 at 02:14:23PM +0530, Sriharsha Allenki wrote:
>> Hi Greg,
>>
>> On 3/26/2020 1:46 PM, Greg KH wrote:
>>> On Thu, Mar 26, 2020 at 11:30:33AM +0530, Sriharsha Allenki wrote:
>>>> In AIO case, the request is freed up if ep_queue fails.
>>>> However, io_data->req still has the reference to this freed
>>>> request. In the case of this failure if there is aio_cancel
>>>> call on this io_data it will lead to an invalid dequeue
>>>> operation and a potential use after free issue.
>>>> Fix this by setting the io_data->req to NULL when the request
>>>> is freed as part of queue failure.
>>>>
>>>> Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>
>>>> ---
>>>>  drivers/usb/gadget/function/f_fs.c | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
>>>> index 571917677d35..767f30b86645 100644
>>>> --- a/drivers/usb/gadget/function/f_fs.c
>>>> +++ b/drivers/usb/gadget/function/f_fs.c
>>>> @@ -1120,6 +1120,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
>>>>  
>>>>  		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
>>>>  		if (unlikely(ret)) {
>>>> +			io_data->req = NULL;
>>>>  			usb_ep_free_request(ep->ep, req);
>>>>  			goto error_lock;
>>>>  		}
>>>> -- 
>>>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
>>> What commit does this fix?  Should it go to stable kernels, and if so,
>>> how far back?
>> The commit 2e4c7553cd6f ("usb: gadget: f_fs: add aio support") introduced
>> the problem. It is good to have in stable kernels and it needs to go all
>> theway back to linux-3.15.y.
>>
>> Hope this information helps.
> Great, please resend this with the proper Fixes: and cc: stable... tag
> on it so that it gets picked up properly.
Thanks Greg for review. Sent out v2 patch with the updated tags.
> thanks,
>
> greg k-h
Regards,
Sriharsha

^ permalink raw reply	[flat|nested] 6+ messages in thread

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Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-26  6:00 [PATCH] usb: gadget: f_fs: Fix use after free issue as part of queue failure Sriharsha Allenki
2020-03-26  8:16 ` Greg KH
2020-03-26  8:44   ` Sriharsha Allenki
2020-03-26  9:30     ` Greg KH
2020-03-26 12:33       ` Sriharsha Allenki
2020-03-26 11:19 ` Peter Chen

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