diff --git a/repos/dde_linux/src/drivers/usb/raw/raw.cc b/repos/dde_linux/src/drivers/usb/raw/raw.cc
index efa86bf29b..564fea4aeb 100644
--- a/repos/dde_linux/src/drivers/usb/raw/raw.cc
+++ b/repos/dde_linux/src/drivers/usb/raw/raw.cc
@@ -341,6 +341,14 @@ class Usb::Worker : public Genode::Weak_object<Usb::Worker>
 
 				usb_host_endpoint *ep = read ? _device->udev->ep_in[p.transfer.ep & 0x0f]
 				                             : _device->udev->ep_out[p.transfer.ep & 0x0f];
+
+				if (!ep) {
+					error("could not get ep: ", p.transfer.ep);
+					dma_free(buf);
+					p.error = Usb::Packet_descriptor::SUBMIT_ERROR;
+					return false;
+				}
+
 				polling_interval = ep->desc.bInterval;
 
 			} else
@@ -382,6 +390,13 @@ class Usb::Worker : public Genode::Weak_object<Usb::Worker>
 				Genode::memcpy(buf, _sink->packet_content(p), p.size());
 			}
 
+			if (!ep) {
+				error("could not get ep: ", p.transfer.ep);
+				dma_free(buf);
+				p.error = Usb::Packet_descriptor::SUBMIT_ERROR;
+				return false;
+			}
+
 			urb *urb = usb_alloc_urb(p.transfer.number_of_packets, GFP_KERNEL);
 			if (!urb) {
 				error("Failed to allocate isochronous URB");
diff --git a/repos/dde_linux/src/drivers/usb_host/raw.cc b/repos/dde_linux/src/drivers/usb_host/raw.cc
index 4aa4b213d6..1d3b87684c 100644
--- a/repos/dde_linux/src/drivers/usb_host/raw.cc
+++ b/repos/dde_linux/src/drivers/usb_host/raw.cc
@@ -352,6 +352,14 @@ class Usb::Worker : public Genode::Weak_object<Usb::Worker>
 
 				usb_host_endpoint *ep = read ? _device->udev->ep_in[p.transfer.ep & 0x0f]
 				                             : _device->udev->ep_out[p.transfer.ep & 0x0f];
+
+				if (!ep) {
+					error("could not get ep: ", p.transfer.ep);
+					dma_free(buf);
+					p.error = Usb::Packet_descriptor::SUBMIT_ERROR;
+					return false;
+				}
+
 				polling_interval = ep->desc.bInterval;
 
 			} else
@@ -393,6 +401,13 @@ class Usb::Worker : public Genode::Weak_object<Usb::Worker>
 				Genode::memcpy(buf, _sink->packet_content(p), p.size());
 			}
 
+			if (!ep) {
+				error("could not get ep: ", p.transfer.ep);
+				dma_free(buf);
+				p.error = Usb::Packet_descriptor::SUBMIT_ERROR;
+				return false;
+			}
+
 			urb *urb = usb_alloc_urb(p.transfer.number_of_packets, GFP_KERNEL);
 			if (!urb) {
 				error("Failed to allocate isochronous URB");