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| author | Hans Verkuil <hverkuil@xs4all.nl> | 2011-09-06 10:23:18 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-09-21 22:17:43 -0300 |
| commit | 8280b662df96f4172c4972b14a4aec0daf272b8f (patch) | |
| tree | 774e688fe12b1cbbc2495f7a250fe4901d0bec6f | |
| parent | dd182e5416e872e30d90cf071758eec1cf6340d5 (diff) | |
| download | op-kernel-dev-8280b662df96f4172c4972b14a4aec0daf272b8f.zip op-kernel-dev-8280b662df96f4172c4972b14a4aec0daf272b8f.tar.gz | |
[media] v4l: Fix use-after-free case in v4l2_device_release
Drivers that have no v4l2_device release callback might free the
v4l2_device instance in the video_device release callback. Make sure we
don't access the v4l2_device instance after it gets freed.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | drivers/media/video/v4l2-dev.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 06f1400..d721565 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -173,6 +173,17 @@ static void v4l2_device_release(struct device *cd) media_device_unregister_entity(&vdev->entity); #endif + /* Do not call v4l2_device_put if there is no release callback set. + * Drivers that have no v4l2_device release callback might free the + * v4l2_dev instance in the video_device release callback below, so we + * must perform this check here. + * + * TODO: In the long run all drivers that use v4l2_device should use the + * v4l2_device release callback. This check will then be unnecessary. + */ + if (v4l2_dev->release == NULL) + v4l2_dev = NULL; + /* Release video_device and perform other cleanups as needed. */ vdev->release(vdev); |
