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| author | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2016-04-28 01:28:26 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-06-15 23:57:24 +0300 |
| commit | a087ce704b802becbb4b0f2a20f2cb3f6911802e (patch) | |
| tree | 6cfa3f4ac4ef03bc7f7cc5fe4180a956f470213b /include/media/media-device.h | |
| parent | 163f1e93e995048b894c5fc86a6034d16beed740 (diff) | |
| download | linux-a087ce704b802becbb4b0f2a20f2cb3f6911802e.tar.xz | |
[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 'include/media/media-device.h')
| -rw-r--r-- | include/media/media-device.h | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/include/media/media-device.h b/include/media/media-device.h index a9b33c47310d..f743ae2210ee 100644 --- a/include/media/media-device.h +++ b/include/media/media-device.h @@ -347,7 +347,7 @@ struct media_entity_notify { struct media_device { /* dev->driver_data points to this struct. */ struct device *dev; - struct media_devnode devnode; + struct media_devnode *devnode; char model[32]; char driver_name[32]; @@ -393,9 +393,6 @@ struct usb_device; #define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0 #define MEDIA_DEV_NOTIFY_POST_LINK_CH 1 -/* media_devnode to media_device */ -#define to_media_device(node) container_of(node, struct media_device, devnode) - /** * media_entity_enum_init - Initialise an entity enumeration * |