target/linux/brcm2708/patches-4.4/0317-videobuf2-v4l2-Verify-planes-array-in-buffer-dequeue.patch

   1 From b9e91e565c8c05abec932a3d1bcb9bab81570ad6 Mon Sep 17 00:00:00 2001
   2 From: Sakari Ailus <sakari.ailus@linux.intel.com>
   3 Date: Sun, 3 Apr 2016 16:31:03 -0300
   4 Subject: [PATCH 317/423] videobuf2-v4l2: Verify planes array in buffer
   5  dequeueing
   6
   7 commit 2c1f6951a8a82e6de0d82b1158b5e493fc6c54ab upstream.
   8
   9 When a buffer is being dequeued using VIDIOC_DQBUF IOCTL, the exact buffer
  10 which will be dequeued is not known until the buffer has been removed from
  11 the queue. The number of planes is specific to a buffer, not to the queue.
  12
  13 This does lead to the situation where multi-plane buffers may be requested
  14 and queued with n planes, but VIDIOC_DQBUF IOCTL may be passed an argument
  15 struct with fewer planes.
  16
  17 __fill_v4l2_buffer() however uses the number of planes from the dequeued
  18 videobuf2 buffer, overwriting kernel memory (the m.planes array allocated
  19 in video_usercopy() in v4l2-ioctl.c)  if the user provided fewer
  20 planes than the dequeued buffer had. Oops!
  21
  22 Fixes: b0e0e1f83de3 ("[media] media: videobuf2: Prepare to divide videobuf2")
  23
  24 Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
  25 Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
  26 Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28 ---
  29  drivers/media/v4l2-core/videobuf2-v4l2.c | 6 ++++++
  30  1 file changed, 6 insertions(+)
  31
  32 --- a/drivers/media/v4l2-core/videobuf2-v4l2.c
  33 +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
  34 @@ -67,6 +67,11 @@ static int __verify_planes_array(struct
  35         return 0;
  36  }
  37
  38 +static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
  39 +{
  40 +       return __verify_planes_array(vb, pb);
  41 +}
  42 +
  43  /**
  44   * __verify_length() - Verify that the bytesused value for each plane fits in
  45   * the plane length and that the data offset doesn't exceed the bytesused value.
  46 @@ -432,6 +437,7 @@ static int __fill_vb2_buffer(struct vb2_
  47  }
  48
  49  static const struct vb2_buf_ops v4l2_buf_ops = {
  50 +       .verify_planes_array    = __verify_planes_array_core,
  51         .fill_user_buffer       = __fill_v4l2_buffer,
  52         .fill_vb2_buffer        = __fill_vb2_buffer,
  53         .set_timestamp          = __set_timestamp,