| Message ID | 1459943168-18406-3-git-send-email-sakari.ailus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 04/06/2016 04:46 AM, Sakari Ailus wrote: > When a buffer is being dequeued using VIDIOC_DQBUF IOCTL, the exact buffer > which will be dequeued is not known until the buffer has been removed from > the queue. The number of planes is specific to a buffer, not to the queue. > > This does lead to the situation where multi-plane buffers may be requested > and queued with n planes, but VIDIOC_DQBUF IOCTL may be passed an argument > struct with fewer planes. > > __fill_v4l2_buffer() however uses the number of planes from the dequeued > videobuf2 buffer, overwriting kernel memory (the m.planes array allocated > in video_usercopy() in v4l2-ioctl.c) if the user provided fewer > planes than the dequeued buffer had. Oops! > > Fixes: b0e0e1f83de3 ("[media] media: videobuf2: Prepare to divide videobuf2") > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Thanks, Hans > --- > drivers/media/v4l2-core/videobuf2-v4l2.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c > index 91f5521..8da7470 100644 > --- a/drivers/media/v4l2-core/videobuf2-v4l2.c > +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c > @@ -74,6 +74,11 @@ static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer > return 0; > } > > +static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb) > +{ > + return __verify_planes_array(vb, pb); > +} > + > /** > * __verify_length() - Verify that the bytesused value for each plane fits in > * the plane length and that the data offset doesn't exceed the bytesused value. > @@ -437,6 +442,7 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, > } > > static const struct vb2_buf_ops v4l2_buf_ops = { > + .verify_planes_array = __verify_planes_array_core, > .fill_user_buffer = __fill_v4l2_buffer, > .fill_vb2_buffer = __fill_vb2_buffer, > .copy_timestamp = __copy_timestamp, > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c index 91f5521..8da7470 100644 --- a/drivers/media/v4l2-core/videobuf2-v4l2.c +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c @@ -74,6 +74,11 @@ static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer return 0; } +static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb) +{ + return __verify_planes_array(vb, pb); +} + /** * __verify_length() - Verify that the bytesused value for each plane fits in * the plane length and that the data offset doesn't exceed the bytesused value. @@ -437,6 +442,7 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, } static const struct vb2_buf_ops v4l2_buf_ops = { + .verify_planes_array = __verify_planes_array_core, .fill_user_buffer = __fill_v4l2_buffer, .fill_vb2_buffer = __fill_vb2_buffer, .copy_timestamp = __copy_timestamp,
When a buffer is being dequeued using VIDIOC_DQBUF IOCTL, the exact buffer which will be dequeued is not known until the buffer has been removed from the queue. The number of planes is specific to a buffer, not to the queue. This does lead to the situation where multi-plane buffers may be requested and queued with n planes, but VIDIOC_DQBUF IOCTL may be passed an argument struct with fewer planes. __fill_v4l2_buffer() however uses the number of planes from the dequeued videobuf2 buffer, overwriting kernel memory (the m.planes array allocated in video_usercopy() in v4l2-ioctl.c) if the user provided fewer planes than the dequeued buffer had. Oops! Fixes: b0e0e1f83de3 ("[media] media: videobuf2: Prepare to divide videobuf2") Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> --- drivers/media/v4l2-core/videobuf2-v4l2.c | 6 ++++++ 1 file changed, 6 insertions(+)