8 files changed, 234 insertions, 48 deletions

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 75912ce6ab55..44218be1e676 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -288,6 +288,7 @@ static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data);
 static void ffs_release_dev(struct ffs_dev *ffs_dev);
 static int ffs_ready(struct ffs_data *ffs);
 static void ffs_closed(struct ffs_data *ffs);
+static void ffs_reset_work(struct work_struct *work);
 
 /* Misc helper functions ****************************************************/
 
@@ -1374,7 +1375,6 @@ ffs_epfile_release(struct inode *inode, struct file *file)
 
 	mutex_unlock(&epfile->dmabufs_mutex);
 
-	__ffs_epfile_read_buffer_free(epfile);
 	ffs_data_closed(epfile->ffs);
 
 	return 0;
@@ -1704,6 +1704,7 @@ 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. */
@@ -2221,6 +2222,7 @@ static struct ffs_data *ffs_data_new(const char *dev_name)
 	init_waitqueue_head(&ffs->ev.waitq);
 	init_waitqueue_head(&ffs->wait);
 	init_completion(&ffs->ep0req_completion);
+	INIT_WORK(&ffs->reset_work, ffs_reset_work);
 
 	/* XXX REVISIT need to update it in some places, or do we? */
 	ffs->ev.can_stall = 1;
@@ -2364,6 +2366,7 @@ 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;
 		err = ffs_sb_create_file(ffs->sb, epfile->name,
 					 epfile, &ffs_epfile_operations);
 		if (err) {
@@ -2389,6 +2392,7 @@ static void ffs_epfiles_destroy(struct super_block *sb,
 
 	for (; count; --count, ++epfile) {
 		BUG_ON(mutex_is_locked(&epfile->mutex));
+		__ffs_epfile_read_buffer_free(epfile);
 		simple_remove_by_name(root, epfile->name, clear_one);
 	}
 
@@ -2453,7 +2457,6 @@ 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;
@@ -3775,7 +3778,6 @@ static int ffs_func_set_alt(struct usb_function *f,
 	if (ffs->state == FFS_DEACTIVATED) {
 		ffs->state = FFS_CLOSING;
 		spin_unlock_irqrestore(&ffs->eps_lock, flags);
-		INIT_WORK(&ffs->reset_work, ffs_reset_work);
 		schedule_work(&ffs->reset_work);
 		return -ENODEV;
 	}
@@ -3806,7 +3808,6 @@ static void ffs_func_disable(struct usb_function *f)
 	if (ffs->state == FFS_DEACTIVATED) {
 		ffs->state = FFS_CLOSING;
 		spin_unlock_irqrestore(&ffs->eps_lock, flags);
-		INIT_WORK(&ffs->reset_work, ffs_reset_work);
 		schedule_work(&ffs->reset_work);
 		return;
 	}
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 4d9e4bd700d8..fba8cf787d6c 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -1309,6 +1309,7 @@ static void f_midi_free(struct usb_function *f)
 	opts = container_of(f->fi, struct f_midi_opts, func_inst);
 	mutex_lock(&opts->lock);
 	if (!--midi->free_ref) {
+		cancel_work_sync(&midi->work);
 		kfree(midi->id);
 		kfifo_free(&midi->in_req_fifo);
 		kfree(midi);
diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c
index c5bf8a448d64..bf02545b37a2 100644
--- a/drivers/usb/gadget/function/f_ncm.c
+++ b/drivers/usb/gadget/function/f_ncm.c
@@ -1171,7 +1171,7 @@ static int ncm_unwrap_ntb(struct gether *port,
 	unsigned char	*ntb_ptr = skb->data;
 	__le16		*tmp;
 	unsigned	index, index2;
-	int		ndp_index;
+	unsigned int	ndp_index;
 	unsigned	dg_len, dg_len2;
 	unsigned	ndp_len;
 	unsigned	block_len;
@@ -1189,6 +1189,10 @@ static int ncm_unwrap_ntb(struct gether *port,
 	frame_max = ncm_opts->max_segment_size;
 
 parse_ntb:
+	if (to_process < (int)opts->nth_size) {
+		INFO(port->func.config->cdev, "Packet too small for headers\n");
+		goto err;
+	}
 	tmp = (__le16 *)ntb_ptr;
 
 	/* dwSignature */
@@ -1209,8 +1213,12 @@ parse_ntb:
 	tmp++; /* skip wSequence */
 
 	block_len = get_ncm(&tmp, opts->block_length);
+	if (block_len == 0)
+		block_len = to_process;
+
 	/* (d)wBlockLength */
-	if ((block_len < opts->nth_size + opts->ndp_size) || (block_len > ntb_max)) {
+	if ((block_len < opts->nth_size + opts->ndp_size) || (block_len > ntb_max) ||
+			(block_len > to_process)) {
 		INFO(port->func.config->cdev, "Bad block length: %#X\n", block_len);
 		goto err;
 	}
@@ -1273,7 +1281,7 @@ parse_ntb:
 			index = index2;
 			/* wDatagramIndex[0] */
 			if ((index < opts->nth_size) ||
-					(index > block_len - opts->dpe_size)) {
+					(index > block_len)) {
 				INFO(port->func.config->cdev,
 				     "Bad index: %#X\n", index);
 				goto err;
@@ -1285,7 +1293,8 @@ parse_ntb:
 			 * ethernet hdr + crc or larger than max frame size
 			 */
 			if ((dg_len < 14 + crc_len) ||
-					(dg_len > frame_max)) {
+					(dg_len > frame_max) ||
+					(dg_len > block_len - index)) {
 				INFO(port->func.config->cdev,
 				     "Bad dgram length: %#X\n", dg_len);
 				goto err;
@@ -1310,7 +1319,7 @@ parse_ntb:
 			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
 
 			/* wDatagramIndex[1] */
-			if (index2 > block_len - opts->dpe_size) {
+			if (index2 > block_len) {
 				INFO(port->func.config->cdev,
 				     "Bad index: %#X\n", index2);
 				goto err;
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index e4f7828ae75d..1857d786110b 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;
 }
 
@@ -432,7 +431,7 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 {
 	struct printer_dev		*dev = fd->private_data;
 	unsigned long			flags;
-	size_t				size;
+	size_t				size, not_copied, copied;
 	size_t				bytes_copied;
 	struct usb_request		*req;
 	/* This is a pointer to the current USB rx request. */
@@ -525,10 +524,12 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 		else
 			size = len;
 
-		size -= copy_to_user(buf, current_rx_buf, size);
-		bytes_copied += size;
-		len -= size;
-		buf += size;
+		not_copied = copy_to_user(buf, current_rx_buf, size);
+		copied = size - not_copied;
+
+		bytes_copied += copied;
+		len -= copied;
+		buf += copied;
 
 		spin_lock_irqsave(&dev->lock, flags);
 
@@ -543,6 +544,17 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 		if (dev->interface < 0)
 			goto out_disabled;
 
+		if (!copied) {
+			dev->current_rx_req = current_rx_req;
+			dev->current_rx_bytes = current_rx_bytes;
+			dev->current_rx_buf = current_rx_buf;
+			spin_unlock_irqrestore(&dev->lock, flags);
+			mutex_unlock(&dev->lock_printer_io);
+			return bytes_copied ? bytes_copied : -EFAULT;
+		}
+
+		size = copied;
+
 		/* If we not returning all the data left in this RX request
 		 * buffer then adjust the amount of data left in the buffer.
 		 * Othewise if we are done with this RX request buffer then
diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index 34d9f49e9987..b3fa5a17fd2d 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -2363,31 +2363,158 @@ ep_fail:
 	return -ENOTSUPP;
 }
 
-struct guas_setup_wq {
-	struct work_struct work;
-	struct f_uas *fu;
-	unsigned int alt;
-};
+static void tcm_cleanup_old_alt(struct f_uas *fu)
+{
+	if (fu->flags & USBG_IS_UAS)
+		uasp_cleanup_old_alt(fu);
+	else if (fu->flags & USBG_IS_BOT)
+		bot_cleanup_old_alt(fu);
+	fu->flags = 0;
+}
+
+static void tcm_delayed_set_alt_done(struct f_uas *fu)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+	fu->delayed_set_alt_state = USBG_DELAYED_SET_ALT_IDLE;
+	fu->delayed_set_alt_cancel = false;
+	spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+}
+
+static bool tcm_delayed_set_alt_cancelled(struct f_uas *fu)
+{
+	bool cancelled;
+	unsigned long flags;
+
+	spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+	cancelled = fu->delayed_set_alt_cancel;
+	spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+
+	return cancelled;
+}
+
+static bool tcm_complete_delayed_status(struct f_uas *fu)
+{
+	struct usb_composite_dev *cdev = fu->function.config->cdev;
+	struct usb_request *req = cdev->req;
+	unsigned long cdev_flags;
+	bool cancelled;
+	int ret;
+
+	spin_lock_irqsave(&cdev->lock, cdev_flags);
+	spin_lock(&fu->delayed_set_alt_lock);
+	cancelled = fu->delayed_set_alt_cancel;
+	if (!cancelled) {
+		fu->delayed_set_alt_state = USBG_DELAYED_SET_ALT_IDLE;
+		fu->delayed_set_alt_cancel = false;
+	}
+	spin_unlock(&fu->delayed_set_alt_lock);
+
+	if (cancelled) {
+		spin_unlock_irqrestore(&cdev->lock, cdev_flags);
+		return false;
+	}
+
+	if (cdev->delayed_status == 0) {
+		WARN(cdev, "%s: Unexpected call\n", __func__);
+	} else if (--cdev->delayed_status == 0) {
+		req->length = 0;
+		req->context = cdev;
+		ret = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+		if (ret == 0) {
+			cdev->setup_pending = true;
+		} else {
+			req->status = 0;
+			req->complete(cdev->gadget->ep0, req);
+		}
+	}
+
+	spin_unlock_irqrestore(&cdev->lock, cdev_flags);
+
+	return true;
+}
+
+static bool tcm_cancel_delayed_set_alt(struct f_uas *fu)
+{
+	bool cleanup = false;
+	bool cancel = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+	switch (fu->delayed_set_alt_state) {
+	case USBG_DELAYED_SET_ALT_IDLE:
+		cleanup = true;
+		break;
+	case USBG_DELAYED_SET_ALT_QUEUED:
+	case USBG_DELAYED_SET_ALT_RUNNING:
+		fu->delayed_set_alt_cancel = true;
+		cancel = true;
+		break;
+	}
+	spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+
+	if (cancel && cancel_work(&fu->delayed_set_alt)) {
+		spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+		if (fu->delayed_set_alt_state == USBG_DELAYED_SET_ALT_QUEUED) {
+			fu->delayed_set_alt_state = USBG_DELAYED_SET_ALT_IDLE;
+			fu->delayed_set_alt_cancel = false;
+			cleanup = true;
+		}
+		spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+	}
+
+	return cleanup;
+}
+
+static void tcm_cancel_delayed_set_alt_sync(struct f_uas *fu)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+	if (fu->delayed_set_alt_state != USBG_DELAYED_SET_ALT_IDLE)
+		fu->delayed_set_alt_cancel = true;
+	spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+
+	cancel_work_sync(&fu->delayed_set_alt);
+
+	spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+	fu->delayed_set_alt_state = USBG_DELAYED_SET_ALT_IDLE;
+	fu->delayed_set_alt_cancel = false;
+	spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+}
 
 static void tcm_delayed_set_alt(struct work_struct *wq)
 {
-	struct guas_setup_wq *work = container_of(wq, struct guas_setup_wq,
-			work);
-	struct f_uas *fu = work->fu;
-	int alt = work->alt;
+	struct f_uas *fu = container_of(wq, struct f_uas, delayed_set_alt);
+	unsigned long flags;
+	unsigned int alt;
 
-	kfree(work);
+	spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+	if (fu->delayed_set_alt_state != USBG_DELAYED_SET_ALT_QUEUED) {
+		spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+		return;
+	}
+	fu->delayed_set_alt_state = USBG_DELAYED_SET_ALT_RUNNING;
+	alt = fu->delayed_alt;
+	spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
 
-	if (fu->flags & USBG_IS_BOT)
-		bot_cleanup_old_alt(fu);
-	if (fu->flags & USBG_IS_UAS)
-		uasp_cleanup_old_alt(fu);
+	tcm_cleanup_old_alt(fu);
+
+	if (tcm_delayed_set_alt_cancelled(fu))
+		goto out_done;
 
 	if (alt == USB_G_ALT_INT_BBB)
 		bot_set_alt(fu);
 	else if (alt == USB_G_ALT_INT_UAS)
 		uasp_set_alt(fu);
-	usb_composite_setup_continue(fu->function.config->cdev);
+
+	if (tcm_complete_delayed_status(fu))
+		return;
+
+	tcm_cleanup_old_alt(fu);
+out_done:
+	tcm_delayed_set_alt_done(fu);
 }
 
 static int tcm_get_alt(struct usb_function *f, unsigned intf)
@@ -2413,15 +2540,20 @@ static int tcm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 		return -EOPNOTSUPP;
 
 	if ((alt == USB_G_ALT_INT_BBB) || (alt == USB_G_ALT_INT_UAS)) {
-		struct guas_setup_wq *work;
+		unsigned long flags;
 
-		work = kmalloc_obj(*work, GFP_ATOMIC);
-		if (!work)
-			return -ENOMEM;
-		INIT_WORK(&work->work, tcm_delayed_set_alt);
-		work->fu = fu;
-		work->alt = alt;
-		schedule_work(&work->work);
+		spin_lock_irqsave(&fu->delayed_set_alt_lock, flags);
+		if (fu->delayed_set_alt_state != USBG_DELAYED_SET_ALT_IDLE) {
+			spin_unlock_irqrestore(&fu->delayed_set_alt_lock,
+					       flags);
+			return -EBUSY;
+		}
+		fu->delayed_alt = alt;
+		fu->delayed_set_alt_cancel = false;
+		fu->delayed_set_alt_state = USBG_DELAYED_SET_ALT_QUEUED;
+		spin_unlock_irqrestore(&fu->delayed_set_alt_lock, flags);
+
+		schedule_work(&fu->delayed_set_alt);
 		return USB_GADGET_DELAYED_STATUS;
 	}
 	return -EOPNOTSUPP;
@@ -2431,11 +2563,8 @@ static void tcm_disable(struct usb_function *f)
 {
 	struct f_uas *fu = to_f_uas(f);
 
-	if (fu->flags & USBG_IS_UAS)
-		uasp_cleanup_old_alt(fu);
-	else if (fu->flags & USBG_IS_BOT)
-		bot_cleanup_old_alt(fu);
-	fu->flags = 0;
+	if (tcm_cancel_delayed_set_alt(fu))
+		tcm_cleanup_old_alt(fu);
 }
 
 static int tcm_setup(struct usb_function *f,
@@ -2583,11 +2712,16 @@ static void tcm_free(struct usb_function *f)
 {
 	struct f_uas *tcm = to_f_uas(f);
 
+	tcm_cancel_delayed_set_alt_sync(tcm);
 	kfree(tcm);
 }
 
 static void tcm_unbind(struct usb_configuration *c, struct usb_function *f)
 {
+	struct f_uas *fu = to_f_uas(f);
+
+	tcm_cancel_delayed_set_alt_sync(fu);
+	tcm_cleanup_old_alt(fu);
 	usb_free_all_descriptors(f);
 }
 
@@ -2620,6 +2754,8 @@ static struct usb_function *tcm_alloc(struct usb_function_instance *fi)
 	fu->function.disable = tcm_disable;
 	fu->function.free_func = tcm_free;
 	fu->tpg = tpg_instances[i].tpg;
+	INIT_WORK(&fu->delayed_set_alt, tcm_delayed_set_alt);
+	spin_lock_init(&fu->delayed_set_alt_lock);
 
 	hash_init(fu->stream_hash);
 	mutex_unlock(&tpg_instances_lock);
diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 3da54a7d7aba..a2fd239b7ad3 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/function/tcm.h b/drivers/usb/gadget/function/tcm.h
index 009974d81d66..e1d5a9391612 100644
--- a/drivers/usb/gadget/function/tcm.h
+++ b/drivers/usb/gadget/function/tcm.h
@@ -3,6 +3,7 @@
 #define __TARGET_USB_GADGET_H__
 
 #include <linux/kref.h>
+#include <linux/spinlock.h>
 /* #include <linux/usb/uas.h> */
 #include <linux/hashtable.h>
 #include <linux/usb/composite.h>
@@ -29,6 +30,12 @@ enum {
 
 #define USB_G_DEFAULT_SESSION_TAGS	USBG_NUM_CMDS
 
+enum {
+	USBG_DELAYED_SET_ALT_IDLE = 0,
+	USBG_DELAYED_SET_ALT_QUEUED,
+	USBG_DELAYED_SET_ALT_RUNNING,
+};
+
 struct tcm_usbg_nexus {
 	struct se_session *tvn_se_sess;
 };
@@ -132,6 +139,12 @@ struct f_uas {
 #define USBG_BOT_CMD_PEND	(1 << 4)
 #define USBG_BOT_WEDGED		(1 << 5)
 
+	struct work_struct	delayed_set_alt;
+	spinlock_t		delayed_set_alt_lock; /* protects delayed_set_alt_* */
+	unsigned int		delayed_alt;
+	unsigned int		delayed_set_alt_state;
+	bool			delayed_set_alt_cancel;
+
 	struct usbg_cdb		cmd[USBG_NUM_CMDS];
 	struct usb_ep		*ep_in;
 	struct usb_ep		*ep_out;
diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index 514e5930b9ca..dfa0521a243a 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -200,6 +200,8 @@ uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
 		return usb_ep_set_halt(cdev->gadget->ep0);
 
 	req->length = min_t(unsigned int, uvc->event_length, data->length);
+	if (req->length > sizeof(data->data))
+		req->length = sizeof(data->data);
 	req->zero = data->length < uvc->event_length;
 
 	memcpy(req->buf, data->data, req->length);