1 files changed, 27 insertions, 23 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index d186d0282a38..58f5fbdb6959 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -104,7 +104,6 @@ int config_ep_by_speed(struct usb_gadget *g,
 			struct usb_function *f,
 			struct usb_ep *_ep)
 {
-	struct usb_composite_dev	*cdev = get_gadget_data(g);
 	struct usb_endpoint_descriptor *chosen_desc = NULL;
 	struct usb_descriptor_header **speed_desc = NULL;
 
@@ -176,8 +175,12 @@ ep_found:
 			_ep->maxburst = comp_desc->bMaxBurst + 1;
 			break;
 		default:
-			if (comp_desc->bMaxBurst != 0)
+			if (comp_desc->bMaxBurst != 0) {
+				struct usb_composite_dev *cdev;
+
+				cdev = get_gadget_data(g);
 				ERROR(cdev, "ep0 bMaxBurst must be 0\n");
+			}
 			_ep->maxburst = 1;
 			break;
 		}
@@ -1325,7 +1328,7 @@ static int count_ext_compat(struct usb_configuration *c)
 	return res;
 }
 
-static void fill_ext_compat(struct usb_configuration *c, u8 *buf)
+static int fill_ext_compat(struct usb_configuration *c, u8 *buf)
 {
 	int i, count;
 
@@ -1352,10 +1355,12 @@ static void fill_ext_compat(struct usb_configuration *c, u8 *buf)
 				buf += 23;
 			}
 			count += 24;
-			if (count >= 4096)
-				return;
+			if (count + 24 >= USB_COMP_EP0_OS_DESC_BUFSIZ)
+				return count;
 		}
 	}
+
+	return count;
 }
 
 static int count_ext_prop(struct usb_configuration *c, int interface)
@@ -1400,25 +1405,20 @@ static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
 	struct usb_os_desc *d;
 	struct usb_os_desc_ext_prop *ext_prop;
 	int j, count, n, ret;
-	u8 *start = buf;
 
 	f = c->interface[interface];
+	count = 10; /* header length */
 	for (j = 0; j < f->os_desc_n; ++j) {
 		if (interface != f->os_desc_table[j].if_id)
 			continue;
 		d = f->os_desc_table[j].os_desc;
 		if (d)
 			list_for_each_entry(ext_prop, &d->ext_prop, entry) {
-				/* 4kB minus header length */
-				n = buf - start;
-				if (n >= 4086)
-					return 0;
-
-				count = ext_prop->data_len +
+				n = ext_prop->data_len +
 					ext_prop->name_len + 14;
-				if (count > 4086 - n)
-					return -EINVAL;
-				usb_ext_prop_put_size(buf, count);
+				if (count + n >= USB_COMP_EP0_OS_DESC_BUFSIZ)
+					return count;
+				usb_ext_prop_put_size(buf, n);
 				usb_ext_prop_put_type(buf, ext_prop->type);
 				ret = usb_ext_prop_put_name(buf, ext_prop->name,
 							    ext_prop->name_len);
@@ -1444,11 +1444,12 @@ static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
 				default:
 					return -EINVAL;
 				}
-				buf += count;
+				buf += n;
+				count += n;
 			}
 	}
 
-	return 0;
+	return count;
 }
 
 /*
@@ -1618,6 +1619,8 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 		 */
 		if (w_value && !f->get_alt)
 			break;
+
+		spin_lock(&cdev->lock);
 		value = f->set_alt(f, w_index, w_value);
 		if (value == USB_GADGET_DELAYED_STATUS) {
 			DBG(cdev,
@@ -1627,6 +1630,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 			DBG(cdev, "delayed_status count %d\n",
 					cdev->delayed_status);
 		}
+		spin_unlock(&cdev->lock);
 		break;
 	case USB_REQ_GET_INTERFACE:
 		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
@@ -1717,6 +1721,7 @@ unknown:
 			req->complete = composite_setup_complete;
 			buf = req->buf;
 			os_desc_cfg = cdev->os_desc_config;
+			w_length = min_t(u16, w_length, USB_COMP_EP0_OS_DESC_BUFSIZ);
 			memset(buf, 0, w_length);
 			buf[5] = 0x01;
 			switch (ctrl->bRequestType & USB_RECIP_MASK) {
@@ -1740,8 +1745,8 @@ unknown:
 					count += 16; /* header */
 					put_unaligned_le32(count, buf);
 					buf += 16;
-					fill_ext_compat(os_desc_cfg, buf);
-					value = w_length;
+					value = fill_ext_compat(os_desc_cfg, buf);
+					value = min_t(u16, w_length, value);
 				}
 				break;
 			case USB_RECIP_INTERFACE:
@@ -1770,8 +1775,7 @@ unknown:
 							      interface, buf);
 					if (value < 0)
 						return value;
-
-					value = w_length;
+					value = min_t(u16, w_length, value);
 				}
 				break;
 			}
@@ -2035,8 +2039,8 @@ int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
 		goto end;
 	}
 
-	/* OS feature descriptor length <= 4kB */
-	cdev->os_desc_req->buf = kmalloc(4096, GFP_KERNEL);
+	cdev->os_desc_req->buf = kmalloc(USB_COMP_EP0_OS_DESC_BUFSIZ,
+					 GFP_KERNEL);
 	if (!cdev->os_desc_req->buf) {
 		ret = PTR_ERR(cdev->os_desc_req->buf);
 		kfree(cdev->os_desc_req);