[PATCH] staging: comedi: drivers: Fix memory leak in gsc_hpdi_auto_attach

[Navid Emamdoost]

In the implementation of gsc_hpdi_auto_attach(), the allocated dma
description is leaks in case of alignment error, or failure of
gsc_hpdi_setup_dma_descriptors() or comedi_alloc_subdevices(). Release
devpriv->dma_desc via dma_free_coherent().

Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
---
 drivers/staging/comedi/drivers/gsc_hpdi.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/comedi/drivers/gsc_hpdi.c b/drivers/staging/comedi/drivers/gsc_hpdi.c
index 4bdf44d82879..c0c7047a6d1b 100644
--- a/drivers/staging/comedi/drivers/gsc_hpdi.c
+++ b/drivers/staging/comedi/drivers/gsc_hpdi.c
@@ -633,16 +633,17 @@ static int gsc_hpdi_auto_attach(struct comedi_device *dev,
 	if (devpriv->dma_desc_phys_addr & 0xf) {
 		dev_warn(dev->class_dev,
 			 " dma descriptors not quad-word aligned (bug)\n");
-		return -EIO;
+		retval = -EIO;
+		goto release_dma_desc;
 	}
 
 	retval = gsc_hpdi_setup_dma_descriptors(dev, 0x1000);
 	if (retval < 0)
-		return retval;
+		goto release_dma_desc;
 
 	retval = comedi_alloc_subdevices(dev, 1);
 	if (retval)
-		return retval;
+		goto release_dma_desc;
 
 	/* Digital I/O subdevice */
 	s = &dev->subdevices[0];
@@ -660,6 +661,15 @@ static int gsc_hpdi_auto_attach(struct comedi_device *dev,
 	s->cancel	= gsc_hpdi_cancel;
 
 	return gsc_hpdi_init(dev);
+
+release_dma_desc:
+	if (devpriv->dma_desc)
+		dma_free_coherent(&pcidev->dev,
+				  sizeof(struct plx_dma_desc) *
+				NUM_DMA_DESCRIPTORS,
+				devpriv->dma_desc,
+				devpriv->dma_desc_phys_addr);
+	return retval;
 }
 
 static void gsc_hpdi_detach(struct comedi_device *dev)
-- 
2.17.1