[PATCH] usb: gadget: pch_udc: add checks for dma mapping errors

[Alexey Khoroshilov]

There are no checks for dma mapping errors in pch_udc.
Tha patch adds the checks and error handling code.
Compile tested only.

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

Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
 drivers/usb/gadget/udc/pch_udc.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/pch_udc.c b/drivers/usb/gadget/udc/pch_udc.c
index 84dcbcd756f0..a305f8392082 100644
--- a/drivers/usb/gadget/udc/pch_udc.c
+++ b/drivers/usb/gadget/udc/pch_udc.c
@@ -1767,7 +1767,7 @@ static struct usb_request *pch_udc_alloc_request(struct usb_ep *usbep,
 	req->req.dma = DMA_ADDR_INVALID;
 	req->dma = DMA_ADDR_INVALID;
 	INIT_LIST_HEAD(&req->queue);
-	if (!ep->dev->dma_addr)
+	if (ep->dev->dma_addr != DMA_ADDR_INVALID)
 		return &req->req;
 	/* ep0 in requests are allocated from data pool here */
 	dma_desc = dma_pool_alloc(ep->dev->data_requests, gfp,
@@ -1879,6 +1879,13 @@ static int pch_udc_pcd_queue(struct usb_ep *usbep, struct usb_request *usbreq,
 							  usbreq->length,
 							  DMA_FROM_DEVICE);
 		}
+		if (dma_mapping_error(&dev->pdev->dev, req->dma)) {
+			req->dma = DMA_ADDR_INVALID;
+			retval = -ENOMEM;
+			if ((unsigned long)(usbreq->buf) & 0x03)
+				kfree(req->buf);
+			goto probe_end;
+		}
 		req->dma_mapped = 1;
 	}
 	if (usbreq->length > 0) {
@@ -2961,6 +2968,10 @@ static int init_dma_pools(struct pch_udc_dev *dev)
 	dev->dma_addr = dma_map_single(&dev->pdev->dev, ep0out_buf,
 				       UDC_EP0OUT_BUFF_SIZE * 4,
 				       DMA_FROM_DEVICE);
+	if (dma_mapping_error(&dev->pdev->dev, dev->dma_addr)) {
+		dev->dma_addr = DMA_ADDR_INVALID;
+		return -ENOMEM;
+	}
 	return 0;
 }
 
@@ -3038,7 +3049,7 @@ static void pch_udc_remove(struct pci_dev *pdev)
 		dma_pool_destroy(dev->stp_requests);
 	}
 
-	if (dev->dma_addr)
+	if (dev->dma_addr != DMA_ADDR_INVALID)
 		dma_unmap_single(&dev->pdev->dev, dev->dma_addr,
 				 UDC_EP0OUT_BUFF_SIZE * 4, DMA_FROM_DEVICE);
 
-- 
2.7.4