aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/staging/comedi
diff options
context:
space:
mode:
authorIan Abbott <abbotti@mev.co.uk>2019-06-26 14:17:39 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-01 08:50:15 +0200
commit7379e6baeddf580d01feca650ec1ad508b6ea8ee (patch)
treeff45d9afbeda00c1f6e6393bde6631e0e846f7d3 /drivers/staging/comedi
parentstaging/most/video: set device_caps in struct video_device (diff)
downloadlinux-dev-7379e6baeddf580d01feca650ec1ad508b6ea8ee.tar.xz
linux-dev-7379e6baeddf580d01feca650ec1ad508b6ea8ee.zip
staging: comedi: amplc_pci230: fix null pointer deref on interrupt
The interrupt handler `pci230_interrupt()` causes a null pointer dereference for a PCI260 card. There is no analog output subdevice for a PCI260. The `dev->write_subdev` subdevice pointer and therefore the `s_ao` subdevice pointer variable will be `NULL` for a PCI260. The following call near the end of the interrupt handler results in the null pointer dereference for a PCI260: comedi_handle_events(dev, s_ao); Fix it by only calling the above function if `s_ao` is valid. Note that the other uses of `s_ao` in the calls `pci230_handle_ao_nofifo(dev, s_ao);` and `pci230_handle_ao_fifo(dev, s_ao);` will never be reached for a PCI260, so they are safe. Fixes: 39064f23284c ("staging: comedi: amplc_pci230: use comedi_handle_events()") Cc: <stable@vger.kernel.org> # v3.19+ Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/comedi')
-rw-r--r--drivers/staging/comedi/drivers/amplc_pci230.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/staging/comedi/drivers/amplc_pci230.c b/drivers/staging/comedi/drivers/amplc_pci230.c
index 65f60c2b702a..f7e673121864 100644
--- a/drivers/staging/comedi/drivers/amplc_pci230.c
+++ b/drivers/staging/comedi/drivers/amplc_pci230.c
@@ -2330,7 +2330,8 @@ static irqreturn_t pci230_interrupt(int irq, void *d)
devpriv->intr_running = false;
spin_unlock_irqrestore(&devpriv->isr_spinlock, irqflags);
- comedi_handle_events(dev, s_ao);
+ if (s_ao)
+ comedi_handle_events(dev, s_ao);
comedi_handle_events(dev, s_ai);
return IRQ_HANDLED;