5 files changed, 50 insertions, 10 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index bb3fa6fa9e8b..e09256304dc0 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1863,9 +1863,10 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 				if (cdev->config)
 					config = cdev->config;
 				else
-					config = list_first_entry(
+					config = list_first_entry_or_null(
 							&cdev->configs,
-						struct usb_configuration, list);
+							struct usb_configuration,
+							list);
 				if (!config)
 					goto done;
 
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 737d60b26e02..5ef9a7a7f3bc 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1684,6 +1684,7 @@ static int ffs_dmabuf_transfer(struct file *file,
 	resv_dir = epfile->in ? DMA_RESV_USAGE_READ : DMA_RESV_USAGE_WRITE;
 
 	dma_resv_add_fence(dmabuf->resv, &fence->base, resv_dir);
+	dma_fence_put(&fence->base);
 	dma_resv_unlock(dmabuf->resv);
 
 	/* Now that the dma_fence is in place, queue the transfer. */
@@ -2353,6 +2354,7 @@ static int ffs_epfiles_create(struct ffs_data *ffs)
 			sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
 		else
 			sprintf(epfile->name, "ep%u", i);
+		epfile->in = (ffs->eps_addrmap[i] & USB_ENDPOINT_DIR_MASK) ? 1 : 0;
 		epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
 						 epfile,
 						 &ffs_epfile_operations);
@@ -2439,7 +2441,6 @@ static int ffs_func_eps_enable(struct ffs_function *func)
 		ret = usb_ep_enable(ep->ep);
 		if (!ret) {
 			epfile->ep = ep;
-			epfile->in = usb_endpoint_dir_in(ep->ep->desc);
 			epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
 		} else {
 			break;
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index d295ade8fa67..a3884afa42b4 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -363,12 +363,11 @@ printer_open(struct inode *inode, struct file *fd)
 		ret = 0;
 		/* Change the printer status to show that it's on-line. */
 		dev->printer_status |= PRINTER_SELECTED;
+		kref_get(&dev->kref);
 	}
 
 	spin_unlock_irqrestore(&dev->lock, flags);
 
-	kref_get(&dev->kref);
-
 	return ret;
 }
 
diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index afd75d72412c..2a52de847d3f 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -591,6 +591,7 @@ static int rndis_init_response(struct rndis_params *params,
 static int rndis_query_response(struct rndis_params *params,
 				rndis_query_msg_type *buf)
 {
+	u32 BufLength, BufOffset;
 	rndis_query_cmplt_type *resp;
 	rndis_resp_t *r;
 
@@ -598,6 +599,13 @@ static int rndis_query_response(struct rndis_params *params,
 	if (!params->dev)
 		return -ENOTSUPP;
 
+	BufLength = le32_to_cpu(buf->InformationBufferLength);
+	BufOffset = le32_to_cpu(buf->InformationBufferOffset);
+	if ((BufLength > RNDIS_MAX_TOTAL_SIZE) ||
+	    (BufOffset > RNDIS_MAX_TOTAL_SIZE) ||
+	    (BufOffset + 8 >= RNDIS_MAX_TOTAL_SIZE))
+		return -EINVAL;
+
 	/*
 	 * we need more memory:
 	 * gen_ndis_query_resp expects enough space for
@@ -614,10 +622,8 @@ static int rndis_query_response(struct rndis_params *params,
 	resp->RequestID = buf->RequestID; /* Still LE in msg buffer */
 
 	if (gen_ndis_query_resp(params, le32_to_cpu(buf->OID),
-			le32_to_cpu(buf->InformationBufferOffset)
-					+ 8 + (u8 *)buf,
-			le32_to_cpu(buf->InformationBufferLength),
-			r)) {
+				BufOffset + 8 + (u8 *)buf,
+				BufLength, r)) {
 		/* OID not supported */
 		resp->Status = cpu_to_le32(RNDIS_STATUS_NOT_SUPPORTED);
 		resp->MessageLength = cpu_to_le32(sizeof *resp);
@@ -1074,6 +1080,12 @@ int rndis_rm_hdr(struct gether *port,
 	/* tmp points to a struct rndis_packet_msg_type */
 	__le32 *tmp = (void *)skb->data;
 
+	/* Need at least MessageType, MessageLength, DataOffset, DataLength */
+	if (skb->len < 16) {
+		dev_kfree_skb_any(skb);
+		return -EINVAL;
+	}
+
 	/* MessageType, MessageLength */
 	if (cpu_to_le32(RNDIS_MSG_PACKET)
 			!= get_unaligned(tmp++)) {
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 8dbe79bdc0f9..ab1bcc5512b2 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -31,8 +31,9 @@ static const struct bus_type gadget_bus_type;
 /**
  * struct usb_udc - describes one usb device controller
  * @driver: the gadget driver pointer. For use by the class code
- * @dev: the child device to the actual controller
  * @gadget: the gadget. For use by the class code
+ * @gadget_release: the gadget's release routine
+ * @dev: the child device to the actual controller
  * @list: for use by the udc class driver
  * @vbus: for udcs who care about vbus status, this value is real vbus status;
  * for udcs who do not care about vbus status, this value is always true
@@ -53,6 +54,7 @@ static const struct bus_type gadget_bus_type;
 struct usb_udc {
 	struct usb_gadget_driver	*driver;
 	struct usb_gadget		*gadget;
+	void				(*gadget_release)(struct device *dev);
 	struct device			dev;
 	struct list_head		list;
 	bool				vbus;
@@ -1356,6 +1358,17 @@ static void usb_udc_nop_release(struct device *dev)
 	dev_vdbg(dev, "%s\n", __func__);
 }
 
+static void usb_gadget_release(struct device *dev)
+{
+	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
+	struct usb_udc *udc = gadget->udc;
+	/* Cache the gadget's release routine to prevent UAF */
+	void (*release)(struct device *dev) = udc->gadget_release;
+
+	put_device(&udc->dev);
+	release(dev);
+}
+
 /**
  * usb_initialize_gadget - initialize a gadget and its embedded struct device
  * @parent: the parent device to this udc. Usually the controller driver's
@@ -1412,6 +1425,14 @@ int usb_add_gadget(struct usb_gadget *gadget)
 	mutex_init(&udc->connect_lock);
 
 	udc->started = false;
+	/*
+	 * Align decoupled lifecycles: take a UDC reference to ensure it
+	 * remains allocated until the gadget is released, requiring an
+	 * override of the gadget's release routine to drop it.
+	 */
+	udc->gadget_release = gadget->dev.release;
+	gadget->dev.release = usb_gadget_release;
+	get_device(&udc->dev);
 
 	mutex_lock(&udc_lock);
 	list_add_tail(&udc->list, &udc_list);
@@ -1456,6 +1477,12 @@ int usb_add_gadget(struct usb_gadget *gadget)
 	mutex_lock(&udc_lock);
 	list_del(&udc->list);
 	mutex_unlock(&udc_lock);
+	/*
+	 * Revert the override and drop the UDC reference to prevent
+	 * leaking the UDC if the gadget was statically allocated.
+	 */
+	gadget->dev.release = udc->gadget_release;
+	put_device(&udc->dev);
 
  err_put_udc:
 	put_device(&udc->dev);