Re: [PATCH v3 07/13] media: controls: Validate H264 stateless controls

[Hans Verkuil]

On 18/11/2020 19:46, Ezequiel Garcia wrote:
> Check that all the fields that correspond or are related
> to a H264 specification syntax element have legal values.
> 
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> ---
>  drivers/media/v4l2-core/v4l2-ctrls.c | 83 ++++++++++++++++++++++++++++
>  1 file changed, 83 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index 21c1928a9df8..adcf47bddbe3 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -1775,6 +1775,9 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
>  {
>  	struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
>  	struct v4l2_ctrl_vp8_frame_header *p_vp8_frame_header;
> +	struct v4l2_ctrl_h264_sps *p_h264_sps;
> +	struct v4l2_ctrl_h264_pps *p_h264_pps;
> +	struct v4l2_ctrl_h264_pred_weights *p_h264_pred_weigths;

weigths -> weights

>  	struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
>  	struct v4l2_ctrl_h264_decode_params *p_h264_dec_params;
>  	struct v4l2_ctrl_hevc_sps *p_hevc_sps;
> @@ -1834,20 +1837,100 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
>  		break;
>  
>  	case V4L2_CTRL_TYPE_H264_SPS:
> +		p_h264_sps = p;
> +
> +		/* Only monochrome and 4:2:0 allowed */
> +		if (p_h264_sps->profile_idc < V4L2_H264_PROFILE_IDC_HIGH_422 &&
> +		    p_h264_sps->chroma_format_idc > 1)
> +				return -EINVAL;
> +		/* 4:2:2 allowed */
> +		else if (p_h264_sps->profile_idc < V4L2_H264_PROFILE_IDC_HIGH_444 &&

You can drop the 'else'.

> +			 p_h264_sps->chroma_format_idc > 2)
> +				return -EINVAL;
> +		else if (p_h264_sps->chroma_format_idc > 3)

Ditto.

> +				return -EINVAL;
> +
> +		if (p_h264_sps->bit_depth_luma_minus8 > 6)
> +			return -EINVAL;
> +		if (p_h264_sps->bit_depth_chroma_minus8 > 6)
> +			return -EINVAL;
> +		if (p_h264_sps->log2_max_frame_num_minus4 > 12)
> +			return -EINVAL;
> +		if (p_h264_sps->pic_order_cnt_type > 2)
> +			return -EINVAL;
> +		if (p_h264_sps->log2_max_pic_order_cnt_lsb_minus4 > 12)
> +			return -EINVAL;
> +		if (p_h264_sps->max_num_ref_frames > V4L2_H264_REF_LIST_LEN)
> +			return -EINVAL;
> +		break;
> +
>  	case V4L2_CTRL_TYPE_H264_PPS:
> +		p_h264_pps = p;
> +
> +		if (p_h264_pps->num_slice_groups_minus1 > 7)
> +			return -EINVAL;
> +		if (p_h264_pps->num_ref_idx_l0_default_active_minus1 >
> +		    (V4L2_H264_REF_LIST_LEN - 1))
> +			return -EINVAL;
> +		if (p_h264_pps->num_ref_idx_l1_default_active_minus1 >
> +		    (V4L2_H264_REF_LIST_LEN - 1))
> +			return -EINVAL;
> +		if (p_h264_pps->weighted_bipred_idc > 2)
> +			return -EINVAL;
> +		/*
> +		 * pic_init_qp_minus26 shall be in the range of
> +		 * -(26 + QpBdOffset_y) to +25, inclusive,
> +		 *  where QpBdOffset_y is 6 * bit_depth_luma_minus8
> +		 */
> +		if (p_h264_pps->pic_init_qp_minus26 < -62 ||
> +		    p_h264_pps->pic_init_qp_minus26 > 25)
> +			return -EINVAL;
> +		if (p_h264_pps->pic_init_qs_minus26 < -26 ||
> +		    p_h264_pps->pic_init_qs_minus26 > 25)
> +			return -EINVAL;
> +		if (p_h264_pps->chroma_qp_index_offset < -12 ||
> +		    p_h264_pps->chroma_qp_index_offset > 12)
> +			return -EINVAL;
> +		if (p_h264_pps->second_chroma_qp_index_offset < -12 ||
> +		    p_h264_pps->second_chroma_qp_index_offset > 12)
> +			return -EINVAL;
> +		break;
> +
>  	case V4L2_CTRL_TYPE_H264_SCALING_MATRIX:
> +		break;
> +
>  	case V4L2_CTRL_TYPE_H264_PRED_WEIGHTS:
> +		p_h264_pred_weigths = p;
> +
> +		if (p_h264_pred_weigths->luma_log2_weight_denom > 7)
> +			return -EINVAL;
> +		if (p_h264_pred_weigths->chroma_log2_weight_denom > 7)
> +			return -EINVAL;
>  		break;
>  
>  	case V4L2_CTRL_TYPE_H264_SLICE_PARAMS:
>  		p_h264_slice_params = p;
>  
> +		if (p_h264_slice_params->colour_plane_id > 2)
> +			return -EINVAL;
> +		if (p_h264_slice_params->cabac_init_idc > 2)
> +			return -EINVAL;
> +		if (p_h264_slice_params->disable_deblocking_filter_idc > 2)
> +			return -EINVAL;
> +		if (p_h264_slice_params->slice_alpha_c0_offset_div2 < -6 ||
> +		    p_h264_slice_params->slice_alpha_c0_offset_div2 > 6)
> +			return -EINVAL;
> +		if (p_h264_slice_params->slice_beta_offset_div2 < -6 ||
> +		    p_h264_slice_params->slice_beta_offset_div2 > 6)
> +			return -EINVAL;
>  		zero_reserved(*p_h264_slice_params);
>  		break;
>  
>  	case V4L2_CTRL_TYPE_H264_DECODE_PARAMS:
>  		p_h264_dec_params = p;
>  
> +		if (p_h264_dec_params->nal_ref_idc > 3)
> +			return -EINVAL;
>  		for (i = 0; i < V4L2_H264_NUM_DPB_ENTRIES; i++) {
>  			struct v4l2_h264_dpb_entry *dpb_entry =
>  				&p_h264_dec_params->dpb[i];
> 

General question: I don't see anything in std_init_compound() for these
controls. Is initializing these compound controls to 0 enough to make them
pass std_validate_compound()? It probably is, otherwise you'd see errors
in the compliance test, I guess.

Regards,

	Hans