staging: most: hdm-usb: fix mbo buffer leak

This patch fixes an MBO leak by replacing the proprietary
free_anchored_buffers() function with the usb_kill_anchored_urbs() function
of the USB subsystem and guarantees that the mbo->complete() completion
function is being called for each URB.

Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/hdm-usb/hdm_usb.c b/drivers/staging/most/hdm-usb/hdm_usb.c
index 70e58c4..1a630e1 100644 (file)
--- a/drivers/staging/most/hdm-usb/hdm_usb.c
+++ b/drivers/staging/most/hdm-usb/hdm_usb.c
@@ -183,30 +183,6 @@ static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
 }
 
 /**
- * free_anchored_buffers - free device's anchored items
- * @mdev: the device
- * @channel: channel ID
- * @status: status of MBO termination
- */
-static void free_anchored_buffers(struct most_dev *mdev, unsigned int channel,
-                                 enum mbo_status_flags status)
-{
-       struct mbo *mbo;
-       struct urb *urb;
-
-       while ((urb = usb_get_from_anchor(&mdev->busy_urbs[channel]))) {
-               mbo = urb->context;
-               usb_kill_urb(urb);
-               if (mbo && mbo->complete) {
-                       mbo->status = status;
-                       mbo->processed_length = 0;
-                       mbo->complete(mbo);
-               }
-               usb_free_urb(urb);
-       }
-}
-
-/**
  * get_stream_frame_size - calculate frame size of current configuration
  * @cfg: channel configuration
  */
@@ -274,7 +250,7 @@ static int hdm_poison_channel(struct most_interface *iface, int channel)
        cancel_work_sync(&mdev->clear_work[channel].ws);
 
        mutex_lock(&mdev->io_mutex);
-       free_anchored_buffers(mdev, channel, MBO_E_CLOSE);
+       usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
        if (mdev->padding_active[channel])
                mdev->padding_active[channel] = false;
 
@@ -373,33 +349,27 @@ static void hdm_write_completion(struct urb *urb)
        unsigned long flags;
 
        spin_lock_irqsave(lock, flags);
-       if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
-           !mdev->is_channel_healthy[channel]) {
-               spin_unlock_irqrestore(lock, flags);
-               return;
-       }
 
-       if (unlikely(urb->status && urb->status != -ESHUTDOWN)) {
-               mbo->processed_length = 0;
+       mbo->processed_length = 0;
+       mbo->status = MBO_E_INVAL;
+       if (likely(mdev->is_channel_healthy[channel])) {
                switch (urb->status) {
+               case 0:
+               case -ESHUTDOWN:
+                       mbo->processed_length = urb->actual_length;
+                       mbo->status = MBO_SUCCESS;
+                       break;
                case -EPIPE:
                        dev_warn(dev, "Broken OUT pipe detected\n");
                        mdev->is_channel_healthy[channel] = false;
-                       spin_unlock_irqrestore(lock, flags);
                        mdev->clear_work[channel].pipe = urb->pipe;
                        schedule_work(&mdev->clear_work[channel].ws);
-                       return;
+                       break;
                case -ENODEV:
                case -EPROTO:
                        mbo->status = MBO_E_CLOSE;
                        break;
-               default:
-                       mbo->status = MBO_E_INVAL;
-                       break;
                }
-       } else {
-               mbo->status = MBO_SUCCESS;
-               mbo->processed_length = urb->actual_length;
        }
 
        spin_unlock_irqrestore(lock, flags);
@@ -527,40 +497,35 @@ static void hdm_read_completion(struct urb *urb)
        unsigned long flags;
 
        spin_lock_irqsave(lock, flags);
-       if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
-           !mdev->is_channel_healthy[channel]) {
-               spin_unlock_irqrestore(lock, flags);
-               return;
-       }
 
-       if (unlikely(urb->status && urb->status != -ESHUTDOWN)) {
-               mbo->processed_length = 0;
+       mbo->processed_length = 0;
+       mbo->status = MBO_E_INVAL;
+       if (likely(mdev->is_channel_healthy[channel])) {
                switch (urb->status) {
+               case 0:
+               case -ESHUTDOWN:
+                       mbo->processed_length = urb->actual_length;
+                       mbo->status = MBO_SUCCESS;
+                       if (mdev->padding_active[channel] &&
+                           hdm_remove_padding(mdev, channel, mbo)) {
+                               mbo->processed_length = 0;
+                               mbo->status = MBO_E_INVAL;
+                       }
+                       break;
                case -EPIPE:
                        dev_warn(dev, "Broken IN pipe detected\n");
                        mdev->is_channel_healthy[channel] = false;
-                       spin_unlock_irqrestore(lock, flags);
                        mdev->clear_work[channel].pipe = urb->pipe;
                        schedule_work(&mdev->clear_work[channel].ws);
-                       return;
+                       break;
                case -ENODEV:
                case -EPROTO:
                        mbo->status = MBO_E_CLOSE;
                        break;
                case -EOVERFLOW:
                        dev_warn(dev, "Babble on IN pipe detected\n");
-               default:
-                       mbo->status = MBO_E_INVAL;
                        break;
                }
-       } else {
-               mbo->processed_length = urb->actual_length;
-               mbo->status = MBO_SUCCESS;
-               if (mdev->padding_active[channel] &&
-                   hdm_remove_padding(mdev, channel, mbo)) {
-                       mbo->processed_length = 0;
-                       mbo->status = MBO_E_INVAL;
-               }
        }
 
        spin_unlock_irqrestore(lock, flags);
@@ -827,7 +792,7 @@ static void wq_clear_halt(struct work_struct *wq_obj)
 
        mutex_lock(&mdev->io_mutex);
        most_stop_enqueue(&mdev->iface, channel);
-       free_anchored_buffers(mdev, channel, MBO_E_INVAL);
+       usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
        if (usb_clear_halt(mdev->usb_device, pipe))
                dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");