Re: [PATCH] usb: gadget: mv_u3d: add check for dma mapping error

[Felipe Balbi]

Hi,

Alexey Khoroshilov  writes:
> mv_u3d_req_to_trb() does not check for dma mapping errors.
>
> By the way, the patch improves readability of mv_u3d_start_queue()
> by rearranging its code with two semantic modifications:
> - assignment zero to ep->processing if usb_gadget_map_request() fails;
> - propagation of error code from mv_u3d_req_to_trb() instead of 
>   hardcoded -ENOMEM.

cleanups and fixes should be done separately.

> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov 
> ---
>  drivers/usb/gadget/udc/mv_u3d_core.c | 34 +-
>  1 file changed, 21 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/usb/gadget/udc/mv_u3d_core.c 
> b/drivers/usb/gadget/udc/mv_u3d_core.c
> index b9e19a591322..8d726bd767fd 100644
> --- a/drivers/usb/gadget/udc/mv_u3d_core.c
> +++ b/drivers/usb/gadget/udc/mv_u3d_core.c
> @@ -462,6 +462,12 @@ static int mv_u3d_req_to_trb(struct mv_u3d_req *req)
>   req->trb_head->trb_hw,
>   trb_num * sizeof(*trb_hw),
>   DMA_BIDIRECTIONAL);
> + if (dma_mapping_error(u3d->gadget.dev.parent,
> + req->trb_head->trb_dma)) {
> + kfree(req->trb_head->trb_hw);
> + kfree(req->trb_head);
> + return -EFAULT;
> + }
>  
>   req->chain = 1;
>   }

this is one patch: add dma_mapping_error() check

AKA $subject :-p

> @@ -487,30 +493,32 @@ mv_u3d_start_queue(struct mv_u3d_ep *ep)
>   ret = usb_gadget_map_request(&u3d->gadget, &req->req,
>   mv_u3d_ep_dir(ep));
>   if (ret)
> - return ret;
> + goto break_processing;
>  
>   req->req.status = -EINPROGRESS;
>   req->req.actual = 0;
>   req->trb_count = 0;
>  
> - /* build trbs and push them to device queue */
> - if (!mv_u3d_req_to_trb(req)) {
> - ret = mv_u3d_queue_trb(ep, req);
> - if (ret) {
> - ep->processing = 0;
> - return ret;
> - }
> - } else {
> - ep->processing = 0;
> + /* build trbs */
> + ret = mv_u3d_req_to_trb(req);
> + if (ret) {
>   dev_err(u3d->dev, "%s, mv_u3d_req_to_trb fail\n", __func__);
> - return -ENOMEM;
> + goto break_processing;
>   }
>  
> + /* and push them to device queue */
> + ret = mv_u3d_queue_trb(ep, req);
> + if (ret)
> + goto break_processing;
> +
>   /* irq handler advances the queue */
> - if (req)
> - list_add_tail(&req->queue, &ep->queue);
> + list_add_tail(&req->queue, &ep->queue);
>  
>   return 0;
> +
> +break_processing:
> + ep->processing = 0;
> + return ret;
>  }
>  
>  static int mv_u3d_ep_enable(struct usb_ep *_ep,

this is another, unrelated patch. Please split

-- 
balbi


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[PATCH] usb: gadget: mv_u3d: add check for dma mapping error

[Alexey Khoroshilov]

mv_u3d_req_to_trb() does not check for dma mapping errors.

By the way, the patch improves readability of mv_u3d_start_queue()
by rearranging its code with two semantic modifications:
- assignment zero to ep->processing if usb_gadget_map_request() fails;
- propagation of error code from mv_u3d_req_to_trb() instead of 
  hardcoded -ENOMEM.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov 
---
 drivers/usb/gadget/udc/mv_u3d_core.c | 34 +-
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/gadget/udc/mv_u3d_core.c 
b/drivers/usb/gadget/udc/mv_u3d_core.c
index b9e19a591322..8d726bd767fd 100644
--- a/drivers/usb/gadget/udc/mv_u3d_core.c
+++ b/drivers/usb/gadget/udc/mv_u3d_core.c
@@ -462,6 +462,12 @@ static int mv_u3d_req_to_trb(struct mv_u3d_req *req)
req->trb_head->trb_hw,
trb_num * sizeof(*trb_hw),
DMA_BIDIRECTIONAL);
+   if (dma_mapping_error(u3d->gadget.dev.parent,
+   req->trb_head->trb_dma)) {
+   kfree(req->trb_head->trb_hw);
+   kfree(req->trb_head);
+   return -EFAULT;
+   }
 
req->chain = 1;
}
@@ -487,30 +493,32 @@ mv_u3d_start_queue(struct mv_u3d_ep *ep)
ret = usb_gadget_map_request(&u3d->gadget, &req->req,
mv_u3d_ep_dir(ep));
if (ret)
-   return ret;
+   goto break_processing;
 
req->req.status = -EINPROGRESS;
req->req.actual = 0;
req->trb_count = 0;
 
-   /* build trbs and push them to device queue */
-   if (!mv_u3d_req_to_trb(req)) {
-   ret = mv_u3d_queue_trb(ep, req);
-   if (ret) {
-   ep->processing = 0;
-   return ret;
-   }
-   } else {
-   ep->processing = 0;
+   /* build trbs */
+   ret = mv_u3d_req_to_trb(req);
+   if (ret) {
dev_err(u3d->dev, "%s, mv_u3d_req_to_trb fail\n", __func__);
-   return -ENOMEM;
+   goto break_processing;
}
 
+   /* and push them to device queue */
+   ret = mv_u3d_queue_trb(ep, req);
+   if (ret)
+   goto break_processing;
+
/* irq handler advances the queue */
-   if (req)
-   list_add_tail(&req->queue, &ep->queue);
+   list_add_tail(&req->queue, &ep->queue);
 
return 0;
+
+break_processing:
+   ep->processing = 0;
+   return ret;
 }
 
 static int mv_u3d_ep_enable(struct usb_ep *_ep,
-- 
2.7.4

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