Commit 2fd2bdfc authored Aug 20, 2013 by Ian Abbott Committed by Greg Kroah-Hartman Aug 22, 2013

staging: comedi: pcmuio: fix possible NULL deref on detach



pcmuio_detach() is called by the comedi core even if pcmuio_attach()
returned an error, so `dev->private` might be `NULL`.  Check for that
before dereferencing it.

Also, as pointed out by Dan Carpenter, there is no need to check the
pointer passed to `kfree()` is non-NULL, so remove that check.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b88e75bb

drivers/staging/comedi/drivers/pcmuio.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -672,12 +672,13 @@ static void pcmuio_detach(struct comedi_device *dev)
		struct pcmuio_private *devpriv = dev->private;
		int i;

		if (devpriv) {
		for (i = 0; i < PCMUIO_MAX_ASICS; ++i) {
		if (devpriv->asics[i].irq)
		free_irq(devpriv->asics[i].irq, dev);
		}
		if (devpriv && devpriv->sprivs)
		kfree(devpriv->sprivs);
		}
		comedi_legacy_detach(dev);
		}