| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.5 118/200] [media] videobuf2-v4l2: Verify planes array in buffer dequeueing | Date | Mon, 2 May 2016 17:11:57 -0700 |
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4.5-stable review patch. If anyone has any objections, please let me know.
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From: Sakari Ailus <sakari.ailus@linux.intel.com>
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 @@ -74,6 +74,11 @@ 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. @@ -437,6 +442,7 @@ 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, .copy_timestamp = __copy_timestamp,
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