diff options
| author | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2016-04-27 19:28:26 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-06-15 17:57:24 -0300 |
| commit | a087ce704b802becbb4b0f2a20f2cb3f6911802e (patch) | |
| tree | 6cfa3f4ac4ef03bc7f7cc5fe4180a956f470213b /drivers/media/usb/au0828 | |
| parent | 163f1e93e995048b894c5fc86a6034d16beed740 (diff) | |
[media] media-device: dynamically allocate struct media_devnode
struct media_devnode is currently embedded at struct media_device.
While this works fine during normal usage, it leads to a race
condition during devnode unregister. the problem is that drivers
assume that, after calling media_device_unregister(), the struct
that contains media_device can be freed. This is not true, as it
can't be freed until userspace closes all opened /dev/media devnodes.
In other words, if the media devnode is still open, and media_device
gets freed, any call to an ioctl will make the core to try to access
struct media_device, with will cause an use-after-free and even GPF.
Fix this by dynamically allocating the struct media_devnode and only
freeing it when it is safe.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media/usb/au0828')
| -rw-r--r-- | drivers/media/usb/au0828/au0828-core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c index 321ea5cf1329..bf53553d2624 100644 --- a/drivers/media/usb/au0828/au0828-core.c +++ b/drivers/media/usb/au0828/au0828-core.c @@ -142,7 +142,7 @@ static void au0828_unregister_media_device(struct au0828_dev *dev) struct media_device *mdev = dev->media_dev; struct media_entity_notify *notify, *nextp; - if (!mdev || !media_devnode_is_registered(&mdev->devnode)) + if (!mdev || !media_devnode_is_registered(mdev->devnode)) return; /* Remove au0828 entity_notify callbacks */ @@ -482,7 +482,7 @@ static int au0828_media_device_register(struct au0828_dev *dev, if (!dev->media_dev) return 0; - if (!media_devnode_is_registered(&dev->media_dev->devnode)) { + if (!media_devnode_is_registered(dev->media_dev->devnode)) { /* register media device */ ret = media_device_register(dev->media_dev); |