[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 <khoroshi...@ispras.ru>
---
 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