[PATCH] usb: cdns3: Fix potential dereference of NULL pointer

[Yongzhi Liu]

The return value of cdns3_gadget_ep_alloc_request()
needs to be checked to avoid use of NULL pointer
in case of an allocation failure.

Fixes: 7733f6c32e36f ("usb: cdns3: Add Cadence USB3 DRD Driver")

Signed-off-by: Yongzhi Liu <lyz_cs@xxxxxxxxxx>
---
 drivers/usb/cdns3/cdns3-gadget.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 5d8c982..7be328e 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2568,6 +2568,10 @@ static int cdns3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
 		struct cdns3_request *priv_req;
 
 		zlp_request = cdns3_gadget_ep_alloc_request(ep, GFP_ATOMIC);
+		if (!zlp_request) {
+			ret = -ENOMEM;
+			goto err;
+		}
 		zlp_request->buf = priv_dev->zlp_buf;
 		zlp_request->length = 0;
 
@@ -2578,7 +2582,7 @@ static int cdns3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
 			priv_ep->name);
 		ret = __cdns3_gadget_ep_queue(ep, zlp_request, gfp_flags);
 	}
-
+err:
 	spin_unlock_irqrestore(&priv_dev->lock, flags);
 	return ret;
 }
-- 
2.7.4