[PATCH] media: fix media_open() to not release lock too soon

From: Shuah Khan
Date: Wed Apr 20 2016 - 16:48:18 EST


media_open() releases media_devnode_lock before open is complete. Hold
the lock to call mdev->fops->open and release at the end.

Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
---
drivers/media/media-devnode.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
index 29409f4..0934789 100644
--- a/drivers/media/media-devnode.c
+++ b/drivers/media/media-devnode.c
@@ -155,7 +155,7 @@ static long media_compat_ioctl(struct file *filp, unsigned int cmd,
static int media_open(struct inode *inode, struct file *filp)
{
struct media_devnode *mdev;
- int ret;
+ int ret = 0;

/* Check if the media device is available. This needs to be done with
* the media_devnode_lock held to prevent an open/unregister race:
@@ -173,7 +173,6 @@ static int media_open(struct inode *inode, struct file *filp)
}
/* and increase the device refcount */
get_device(&mdev->dev);
- mutex_unlock(&media_devnode_lock);

filp->private_data = mdev;

@@ -182,11 +181,12 @@ static int media_open(struct inode *inode, struct file *filp)
if (ret) {
put_device(&mdev->dev);
filp->private_data = NULL;
- return ret;
+ goto done;
}
}
-
- return 0;
+done:
+ mutex_unlock(&media_devnode_lock);
+ return ret;
}

/* Override for the release function */
--
2.5.0