staging: emxx_udc: Add checks for dma_alloc_coherent()

As the dma_alloc_coherent may return NULL, the return value needs to be
checked to avoid NULL poineter dereference.

Signed-off-by: Yuan Can <yuancan@huawei.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Link: https://lore.kernel.org/r/20230119083119.16956-1-yuancan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
index b4e1917..f976584 100644 (file)
--- a/drivers/staging/emxx_udc/emxx_udc.c
+++ b/drivers/staging/emxx_udc/emxx_udc.c
@@ -2587,10 +2587,15 @@ static int nbu2ss_ep_queue(struct usb_ep *_ep,
                req->unaligned = false;
 
        if (req->unaligned) {
-               if (!ep->virt_buf)
+               if (!ep->virt_buf) {
                        ep->virt_buf = dma_alloc_coherent(udc->dev, PAGE_SIZE,
                                                          &ep->phys_buf,
                                                          GFP_ATOMIC | GFP_DMA);
+                       if (!ep->virt_buf) {
+                               spin_unlock_irqrestore(&udc->lock, flags);
+                               return -ENOMEM;
+                       }
+               }
                if (ep->epnum > 0)  {
                        if (ep->direct == USB_DIR_IN)
                                memcpy(ep->virt_buf, req->req.buf,