From f4dd2367f3ad276fe49c89a522267ea5ccb6bf80 Mon Sep 17 00:00:00 2001 From: Ian Abbott 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: # 3.6.x Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- 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]; -- 2.11.0