On Thu, Jan 19, 2023 at 02:34:30AM +0000, Yuan Can wrote:
> As the dma_alloc_coherent may return NULL, the return value needs to be
> checked to avoid NULL poineter dereference.
>
> Fixes: 33aa8d45a4fe ("staging: emxx_udc: Add Emma Mobile USB Gadget driver")
> Signed-off-by: Yuan Can <yuancan@xxxxxxxxxx>
> ---
> changes in v2:
> - do the null pointer check right before the memcpy().
>
No. No. This should be:
diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
index b4e19174bef2..f9765841c4aa 100644
--- 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,
