linux-kernel - [PATCH 07/10] staging: comedi: ni_670x: fix dereference of an invalid pointer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Date:	Fri, 29 Jun 2012 17:39:45 -0700
From:	H Hartley Sweeten <hartleys@...ionengravers.com>
To:	Linux Kernel <linux-kernel@...r.kernel.org>
CC:	<devel@...verdev.osuosl.org>, <abbotti@....co.uk>,
	<fmhess@...rs.sourceforge.net>, <gregkh@...uxfoundation.org>
Subject: [PATCH 07/10] staging: comedi: ni_670x: fix dereference of an invalid pointer

The attach if this driver can fail before the subdevices are
allocated. If the attach fails the comedi core will call the
detach routine to allow the driver to do it's cleanup.

We need to make sure that the subdevice allocation was successful
before trying to dereference subdevice[0] to free the allocated
range table list.

Signed-off-by: H Hartley Sweeten <hsweeten@...ionengravers.com>
Cc: Ian Abbott <abbotti@....co.uk>
Cc: Frank Mori Hess <fmhess@...rs.sourceforge.net>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/staging/comedi/drivers/ni_670x.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/ni_670x.c b/drivers/staging/comedi/drivers/ni_670x.c
index bab9644..46f373a 100644
--- a/drivers/staging/comedi/drivers/ni_670x.c
+++ b/drivers/staging/comedi/drivers/ni_670x.c
@@ -301,8 +301,13 @@ static int ni_670x_attach(struct comedi_device *dev,
 static void ni_670x_detach(struct comedi_device *dev)
 {
 	struct ni_670x_private *devpriv = dev->private;
+	struct comedi_subdevice *s;
 
-	kfree(dev->subdevices[0].range_table_list);
+	if (dev->n_subdevices) {
+		s = dev->subdevices + 0;
+		if (s)
+			kfree(s->range_table_list);
+	}
 	if (devpriv && devpriv->mite)
 		mite_unsetup(devpriv->mite);
 	if (dev->irq)
-- 
1.7.11

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/