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- From 2d8ae9f2f45a2f5b777088cbab6e5ea15744d1d5 Mon Sep 17 00:00:00 2001
- From: Sakari Ailus <sakari.ailus@linux.intel.com>
- Date: Sun, 3 Apr 2016 16:31:03 -0300
- Subject: [PATCH 320/381] videobuf2-v4l2: Verify planes array in buffer
- dequeueing
- commit 2c1f6951a8a82e6de0d82b1158b5e493fc6c54ab upstream.
- 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>
- Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
- Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- ---
- drivers/media/v4l2-core/videobuf2-v4l2.c | 6 ++++++
- 1 file changed, 6 insertions(+)
- --- a/drivers/media/v4l2-core/videobuf2-v4l2.c
- +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
- @@ -67,6 +67,11 @@ static int __verify_planes_array(struct
- 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.
- @@ -432,6 +437,7 @@ static int __fill_vb2_buffer(struct vb2_
- }
-
- 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,
- .set_timestamp = __set_timestamp,
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