From f4dd2367f3ad276fe49c89a522267ea5ccb6bf80 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti@mev.co.uk>
Date: Wed, 3 Oct 2012 16:25:15 +0100
Subject: [PATCH] staging: comedi: 8255_pci: fix possible NULL deref during
detach
`pci_8255_detach()` will be called by the comedi core if
`pci_8255_attach_pci()` returns an error. It currently assumes that
both `board` (assigned from the return value of `comedi_board(dev)`) and
`devpriv` (assigned from `dev->private`) are non-null, but they might
be null, leading to a null pointer dereference.
`pci_8255_detach()` doesn't need to do anything if either `board` or
`devpriv` are null, so just return early in this case.
Cc: <stable@vger.kernel.org> # 3.6.x
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/comedi/drivers/8255_pci.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/staging/comedi/drivers/8255_pci.c b/drivers/staging/comedi/drivers/8255_pci.c
index 7dff3c01dc29..d00aff6671df 100644
--- a/drivers/staging/comedi/drivers/8255_pci.c
+++ b/drivers/staging/comedi/drivers/8255_pci.c
@@ -289,6 +289,8 @@ static void pci_8255_detach(struct comedi_device *dev)
struct comedi_subdevice *s;
int i;
+ if (!board || !devpriv)
+ return;
if (dev->subdevices) {
for (i = 0; i < board->n_8255; i++) {
s = &dev->subdevices[i];
--
2.30.9