From: H Hartley Sweeten <hartleys@visionengravers.com>
Date: Tue, 12 Jun 2012 18:57:45 +0000 (-0700)
Subject: staging: comedi: sanity check num_subdevices parameter in comedi_alloc_subdevices
X-Git-Tag: firefly_0821_release~3680^2~2356^2~824
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7f801c41714729f7741a042de839918be2bb56f0;p=firefly-linux-kernel-4.4.55.git

staging: comedi: sanity check num_subdevices parameter in comedi_alloc_subdevices

It's possible for a couple of the comedi drivers to incorrectly call
comedi_alloc_subdevices with num_subdevices = 0. Add a sanity check
before doing the kcalloc.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbot@mev.co.uk>
Cc: Frank Mori Hess <kmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 979aa0e88997..61161ce8e93f 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -60,6 +60,8 @@ int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
 {
 	int i;
 
+	if (num_subdevices < 1)
+		return -EINVAL;
 	dev->n_subdevices = num_subdevices;
 	dev->subdevices =
 	    kcalloc(num_subdevices, sizeof(struct comedi_subdevice),