follow 2fd2bdfccae61efe18f6b92b6a45fbf936d75b48 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@xxxxxxxxx> --- Applies to 3.6.y to 3.9.y inclusive if any distros want it. --- drivers/staging/comedi/drivers/pcmuio.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcmuio.c b/drivers/staging/comedi/drivers/pcmuio.c index 433270c..e0d795a 100644 --- a/drivers/staging/comedi/drivers/pcmuio.c +++ b/drivers/staging/comedi/drivers/pcmuio.c @@ -952,12 +952,13 @@ static void pcmuio_detach(struct comedi_device *dev) if (dev->iobase) release_region(dev->iobase, ASIC_IOSIZE * board->num_asics); - for (i = 0; i < MAX_ASICS; ++i) { - if (devpriv->asics[i].irq) - free_irq(devpriv->asics[i].irq, dev); - } - if (devpriv && devpriv->sprivs) + if (devpriv) { + for (i = 0; i < MAX_ASICS; ++i) { + if (devpriv->asics[i].irq) + free_irq(devpriv->asics[i].irq, dev); + } kfree(devpriv->sprivs); + } } static const struct pcmuio_board pcmuio_boards[] = { -- 1.8.4.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html