5 files changed, 38 insertions, 11 deletions

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 6bdb570..3507f88 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -315,7 +315,6 @@ static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 				return ret;
 			}
 
-			set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
 			return len;
 		}
 		break;
@@ -847,7 +846,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
 				ret = ep->status;
 				if (io_data->read && ret > 0) {
 					ret = copy_to_iter(data, ret, &io_data->data);
-					if (unlikely(iov_iter_count(&io_data->data)))
+					if (!ret)
 						ret = -EFAULT;
 				}
 			}
@@ -1463,8 +1462,7 @@ static void ffs_data_clear(struct ffs_data *ffs)
 {
 	ENTER();
 
-	if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
-		ffs_closed(ffs);
+	ffs_closed(ffs);
 
 	BUG_ON(ffs->gadget);
 
@@ -3422,9 +3420,13 @@ static int ffs_ready(struct ffs_data *ffs)
 	ffs_obj->desc_ready = true;
 	ffs_obj->ffs_data = ffs;
 
-	if (ffs_obj->ffs_ready_callback)
+	if (ffs_obj->ffs_ready_callback) {
 		ret = ffs_obj->ffs_ready_callback(ffs);
+		if (ret)
+			goto done;
+	}
 
+	set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
 done:
 	ffs_dev_unlock();
 	return ret;
@@ -3443,7 +3445,8 @@ static void ffs_closed(struct ffs_data *ffs)
 
 	ffs_obj->desc_ready = false;
 
-	if (ffs_obj->ffs_closed_callback)
+	if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
+	    ffs_obj->ffs_closed_callback)
 		ffs_obj->ffs_closed_callback(ffs);
 
 	if (!ffs_obj->opts || ffs_obj->opts->no_configfs
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 13dfc99..f7f35a3 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -437,12 +437,20 @@ static int hidg_setup(struct usb_function *f,
 		  | USB_REQ_GET_DESCRIPTOR):
 		switch (value >> 8) {
 		case HID_DT_HID:
+		{
+			struct hid_descriptor hidg_desc_copy = hidg_desc;
+
 			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
+			hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
+			hidg_desc_copy.desc[0].wDescriptorLength =
+				cpu_to_le16(hidg->report_desc_length);
+
 			length = min_t(unsigned short, length,
-						   hidg_desc.bLength);
-			memcpy(req->buf, &hidg_desc, length);
+						   hidg_desc_copy.bLength);
+			memcpy(req->buf, &hidg_desc_copy, length);
 			goto respond;
 			break;
+		}
 		case HID_DT_REPORT:
 			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 			length = min_t(unsigned short, length,
@@ -632,6 +640,10 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 	hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 	hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 	hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	/*
+	 * We can use hidg_desc struct here but we should not relay
+	 * that its content won't change after returning from this function.
+	 */
 	hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 	hidg_desc.desc[0].wDescriptorLength =
 		cpu_to_le16(hidg->report_desc_length);
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 259b656..6316aa5 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -973,7 +973,13 @@ static ssize_t f_midi_opts_id_show(struct f_midi_opts *opts, char *page)
 	int result;
 
 	mutex_lock(&opts->lock);
-	result = strlcpy(page, opts->id, PAGE_SIZE);
+	if (opts->id) {
+		result = strlcpy(page, opts->id, PAGE_SIZE);
+	} else {
+		page[0] = 0;
+		result = 0;
+	}
+
 	mutex_unlock(&opts->lock);
 
 	return result;
diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
index 9719abf..7856b33 100644
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -588,7 +588,10 @@ static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 
 	if (intf == 1) {
 		if (alt == 1) {
-			config_ep_by_speed(cdev->gadget, f, out_ep);
+			err = config_ep_by_speed(cdev->gadget, f, out_ep);
+			if (err)
+				return err;
+
 			usb_ep_enable(out_ep);
 			out_ep->driver_data = audio;
 			audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 89179ab..7ee0579 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -113,6 +113,7 @@ struct gs_port {
 	int write_allocated;
 	struct gs_buf		port_write_buf;
 	wait_queue_head_t	drain_wait;	/* wait while writes drain */
+	bool                    write_busy;
 
 	/* REVISIT this state ... */
 	struct usb_cdc_line_coding port_line_coding;	/* 8-N-1 etc */
@@ -363,7 +364,7 @@ __acquires(&port->port_lock)
 	int			status = 0;
 	bool			do_tty_wake = false;
 
-	while (!list_empty(pool)) {
+	while (!port->write_busy && !list_empty(pool)) {
 		struct usb_request	*req;
 		int			len;
 
@@ -393,9 +394,11 @@ __acquires(&port->port_lock)
 		 * NOTE that we may keep sending data for a while after
 		 * the TTY closed (dev->ioport->port_tty is NULL).
 		 */
+		port->write_busy = true;
 		spin_unlock(&port->port_lock);
 		status = usb_ep_queue(in, req, GFP_ATOMIC);
 		spin_lock(&port->port_lock);
+		port->write_busy = false;
 
 		if (status) {
 			pr_debug("%s: %s %s err %d\n",