On Thu, Jan 19, 2023 at 08:17:12AM +0300, Dan Carpenter wrote:
> 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,
>
Yes, FWIIW, I think so too.
Reviewed-by: Simon Horman <horms@xxxxxxxxxxxx>
