Commit e7a0e839 authored Dec 16, 2019 by Ian Abbott Committed by Greg Kroah-Hartman Dec 31, 2019

staging: comedi: gsc_hpdi: check dma_alloc_coherent() return value



commit ab42b48f32d4c766420c3499ee9c0289b7028182 upstream.

The "auto-attach" handler function `gsc_hpdi_auto_attach()` calls
`dma_alloc_coherent()` in a loop to allocate some DMA data buffers, and
also calls it to allocate a buffer for a DMA descriptor chain.  However,
it does not check the return value of any of these calls.  Change
`gsc_hpdi_auto_attach()` to return `-ENOMEM` if any of these
`dma_alloc_coherent()` calls fail.  This will result in the comedi core
calling the "detach" handler `gsc_hpdi_detach()` as part of the
clean-up, which will call `gsc_hpdi_free_dma()` to free any allocated
DMA coherent memory buffers.

Cc: <stable@vger.kernel.org> #4.6+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20191216110823.216237-1-abbotti@mev.co.uk


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e87d7b18

drivers/staging/comedi/drivers/gsc_hpdi.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -623,6 +623,11 @@ static int gsc_hpdi_auto_attach(struct comedi_device *dev,
		dma_alloc_coherent(&pcidev->dev, DMA_BUFFER_SIZE,
		&devpriv->dio_buffer_phys_addr[i],
		GFP_KERNEL);
		if (!devpriv->dio_buffer[i]) {
		dev_warn(dev->class_dev,
		"failed to allocate DMA buffer\n");
		return -ENOMEM;
		}
		}
		/* allocate dma descriptors */
		devpriv->dma_desc = dma_alloc_coherent(&pcidev->dev,
		@@ -630,6 +635,11 @@ static int gsc_hpdi_auto_attach(struct comedi_device *dev,
		NUM_DMA_DESCRIPTORS,
		&devpriv->dma_desc_phys_addr,
		GFP_KERNEL);
		if (!devpriv->dma_desc) {
		dev_warn(dev->class_dev,
		"failed to allocate DMA descriptors\n");
		return -ENOMEM;
		}
		if (devpriv->dma_desc_phys_addr & 0xf) {
		dev_warn(dev->class_dev,
		" dma descriptors not quad-word aligned (bug)\n");