linux-kernel - [PATCH 1/2] media: au0828 fix to protect enable/disable source set and clear

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <6a4776ad1450ecf6ce73e5c005e0549fc29e7710.1480384155.git.shuahkh@osg.samsung.com>
Date:   Mon, 28 Nov 2016 19:15:13 -0700
From:   Shuah Khan <shuahkh@....samsung.com>
To:     mchehab@...nel.org, mkrufky@...uxtv.org, klock.android@...il.com,
        elfring@...rs.sourceforge.net, max@...mpel.org,
        hans.verkuil@...co.com, javier@....samsung.com,
        chehabrafael@...il.com, sakari.ailus@...ux.intel.com,
        laurent.pinchart+renesas@...asonboard.com
Cc:     Shuah Khan <shuahkh@....samsung.com>, linux-media@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] media: au0828 fix to protect enable/disable source set and clear

Protect enable/disable source set and clear to avoid races with callers.
There is a possibility clear could occur while dvb-core and v4l2 try to
access these handlers.

Signed-off-by: Shuah Khan <shuahkh@....samsung.com>
---
 drivers/media/usb/au0828/au0828-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index bf53553..a1f696a 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -153,9 +153,11 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
 	}
 
 	/* clear enable_source, disable_source */
+	mutex_lock(&mdev->graph_mutex);
 	dev->media_dev->source_priv = NULL;
 	dev->media_dev->enable_source = NULL;
 	dev->media_dev->disable_source = NULL;
+	mutex_unlock(&mdev->graph_mutex);
 
 	media_device_unregister(dev->media_dev);
 	media_device_cleanup(dev->media_dev);
@@ -549,9 +551,11 @@ static int au0828_media_device_register(struct au0828_dev *dev,
 		return ret;
 	}
 	/* set enable_source */
+	mutex_lock(&dev->media_dev->graph_mutex);
 	dev->media_dev->source_priv = (void *) dev;
 	dev->media_dev->enable_source = au0828_enable_source;
 	dev->media_dev->disable_source = au0828_disable_source;
+	mutex_unlock(&dev->media_dev->graph_mutex);
 #endif
 	return 0;
 }
-- 
2.7.4