If cdns3_gadget_ep_alloc_request() fails, a null pointer dereference
occurs. Add a check to prevent it.

Found by code review and compiled on ubuntu 20.04.

Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>
---
 drivers/usb/cdns3/cdns3-gadget.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 168707213ed9..cc2421a34588 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2659,6 +2659,8 @@ 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)
+			return -ENOMEM;
 		zlp_request->buf = priv_dev->zlp_buf;
 		zlp_request->length = 0;
 
-- 
2.25.1

On Wed, Dec 24, 2025 at 05:29:35PM +0800, Haoxiang Li wrote:
> If cdns3_gadget_ep_alloc_request() fails, a null pointer dereference
> occurs. Add a check to prevent it.
> 
> Found by code review and compiled on ubuntu 20.04.

What tool did you use to find this through 'code review'?

And the compile line doesn't help, as I stated before.

And how was this tested?

thanks,

greg k-h