[Intel-gfx] [PATCH 10/10] video/hdmi: Pass buffer size to infoframe unpack functions

Hans Verkuil hverkuil at xs4all.nl
Mon Nov 20 13:36:20 UTC 2017


On 11/13/2017 06:04 PM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> To make sure the infoframe unpack functions don't end up examining
> stack garbage or oopsing, let's pass in the size of the buffer.
> 
> Cc: Thierry Reding <thierry.reding at gmail.com>
> Cc: Hans Verkuil <hans.verkuil at cisco.com>
> Cc: linux-media at vger.kernel.org
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/media/i2c/adv7511.c  |  2 +-
>  drivers/media/i2c/adv7604.c  |  2 +-
>  drivers/media/i2c/adv7842.c  |  2 +-
>  drivers/media/i2c/tc358743.c |  2 +-
>  drivers/video/hdmi.c         | 51 ++++++++++++++++++++++++++++++++------------
>  include/linux/hdmi.h         |  2 +-
>  6 files changed, 42 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/media/i2c/adv7511.c b/drivers/media/i2c/adv7511.c
> index 2817bafc67bf..dec09c18ea34 100644
> --- a/drivers/media/i2c/adv7511.c
> +++ b/drivers/media/i2c/adv7511.c
> @@ -562,7 +562,7 @@ static void log_infoframe(struct v4l2_subdev *sd, const struct adv7511_cfg_read_
>  	buffer[3] = 0;
>  	buffer[3] = hdmi_infoframe_checksum(buffer, len + 4);
>  
> -	if (hdmi_infoframe_unpack(&frame, buffer) < 0) {
> +	if (hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)) < 0) {
>  		v4l2_err(sd, "%s: unpack of %s infoframe failed\n", __func__, cri->desc);
>  		return;
>  	}
> diff --git a/drivers/media/i2c/adv7604.c b/drivers/media/i2c/adv7604.c
> index f289b8aca1da..8500438af0d3 100644
> --- a/drivers/media/i2c/adv7604.c
> +++ b/drivers/media/i2c/adv7604.c
> @@ -2429,7 +2429,7 @@ static int adv76xx_read_infoframe(struct v4l2_subdev *sd, int index,
>  		buffer[i + 3] = infoframe_read(sd,
>  				       adv76xx_cri[index].payload_addr + i);
>  
> -	if (hdmi_infoframe_unpack(frame, buffer) < 0) {
> +	if (hdmi_infoframe_unpack(frame, buffer, sizeof(buffer)) < 0) {
>  		v4l2_err(sd, "%s: unpack of %s infoframe failed\n", __func__,
>  			 adv76xx_cri[index].desc);
>  		return -ENOENT;
> diff --git a/drivers/media/i2c/adv7842.c b/drivers/media/i2c/adv7842.c
> index 65f34e7e146f..fd5d5e84dcbf 100644
> --- a/drivers/media/i2c/adv7842.c
> +++ b/drivers/media/i2c/adv7842.c
> @@ -2576,7 +2576,7 @@ static void log_infoframe(struct v4l2_subdev *sd, struct adv7842_cfg_read_infofr
>  	for (i = 0; i < len; i++)
>  		buffer[i + 3] = infoframe_read(sd, cri->payload_addr + i);
>  
> -	if (hdmi_infoframe_unpack(&frame, buffer) < 0) {
> +	if (hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)) < 0) {
>  		v4l2_err(sd, "%s: unpack of %s infoframe failed\n", __func__, cri->desc);
>  		return;
>  	}
> diff --git a/drivers/media/i2c/tc358743.c b/drivers/media/i2c/tc358743.c
> index e6f5c363ccab..f6a5ebffd9c6 100644
> --- a/drivers/media/i2c/tc358743.c
> +++ b/drivers/media/i2c/tc358743.c
> @@ -453,7 +453,7 @@ static void print_avi_infoframe(struct v4l2_subdev *sd)
>  
>  	i2c_rd(sd, PK_AVI_0HEAD, buffer, HDMI_INFOFRAME_SIZE(AVI));
>  
> -	if (hdmi_infoframe_unpack(&frame, buffer) < 0) {
> +	if (hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)) < 0) {
>  		v4l2_err(sd, "%s: unpack of AVI infoframe failed\n", __func__);
>  		return;
>  	}
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index 65b915ea4936..b5d491014b0b 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -1005,8 +1005,9 @@ EXPORT_SYMBOL(hdmi_infoframe_log);
>  
>  /**
>   * hdmi_avi_infoframe_unpack() - unpack binary buffer to a HDMI AVI infoframe
> - * @buffer: source buffer
>   * @frame: HDMI AVI infoframe
> + * @buffer: source buffer
> + * @size: size of buffer
>   *
>   * Unpacks the information contained in binary @buffer into a structured
>   * @frame of the HDMI Auxiliary Video (AVI) information frame.
> @@ -1016,11 +1017,14 @@ EXPORT_SYMBOL(hdmi_infoframe_log);
>   * Returns 0 on success or a negative error code on failure.
>   */
>  static int hdmi_avi_infoframe_unpack(struct hdmi_avi_infoframe *frame,
> -				     const void *buffer)
> +				     const void *buffer, size_t size)
>  {
>  	const u8 *ptr = buffer;
>  	int ret;
>  
> +	if (size < HDMI_INFOFRAME_SIZE(AVI))
> +		return -EINVAL;
> +
>  	if (ptr[0] != HDMI_INFOFRAME_TYPE_AVI ||
>  	    ptr[1] != 2 ||
>  	    ptr[2] != HDMI_AVI_INFOFRAME_SIZE)
> @@ -1068,8 +1072,9 @@ static int hdmi_avi_infoframe_unpack(struct hdmi_avi_infoframe *frame,
>  
>  /**
>   * hdmi_spd_infoframe_unpack() - unpack binary buffer to a HDMI SPD infoframe
> - * @buffer: source buffer
>   * @frame: HDMI SPD infoframe
> + * @buffer: source buffer
> + * @size: size of buffer
>   *
>   * Unpacks the information contained in binary @buffer into a structured
>   * @frame of the HDMI Source Product Description (SPD) information frame.
> @@ -1079,11 +1084,14 @@ static int hdmi_avi_infoframe_unpack(struct hdmi_avi_infoframe *frame,
>   * Returns 0 on success or a negative error code on failure.
>   */
>  static int hdmi_spd_infoframe_unpack(struct hdmi_spd_infoframe *frame,
> -				     const void *buffer)
> +				     const void *buffer, size_t size)
>  {
>  	const u8 *ptr = buffer;
>  	int ret;
>  
> +	if (size < HDMI_INFOFRAME_SIZE(SPD))
> +		return -EINVAL;
> +
>  	if (ptr[0] != HDMI_INFOFRAME_TYPE_SPD ||
>  	    ptr[1] != 1 ||
>  	    ptr[2] != HDMI_SPD_INFOFRAME_SIZE) {
> @@ -1106,8 +1114,9 @@ static int hdmi_spd_infoframe_unpack(struct hdmi_spd_infoframe *frame,
>  
>  /**
>   * hdmi_audio_infoframe_unpack() - unpack binary buffer to a HDMI AUDIO infoframe
> - * @buffer: source buffer
>   * @frame: HDMI Audio infoframe
> + * @buffer: source buffer
> + * @size: size of buffer
>   *
>   * Unpacks the information contained in binary @buffer into a structured
>   * @frame of the HDMI Audio information frame.
> @@ -1117,11 +1126,14 @@ static int hdmi_spd_infoframe_unpack(struct hdmi_spd_infoframe *frame,
>   * Returns 0 on success or a negative error code on failure.
>   */
>  static int hdmi_audio_infoframe_unpack(struct hdmi_audio_infoframe *frame,
> -				       const void *buffer)
> +				       const void *buffer, size_t size)
>  {
>  	const u8 *ptr = buffer;
>  	int ret;
>  
> +	if (size < HDMI_INFOFRAME_SIZE(AUDIO))
> +		return -EINVAL;
> +
>  	if (ptr[0] != HDMI_INFOFRAME_TYPE_AUDIO ||
>  	    ptr[1] != 1 ||
>  	    ptr[2] != HDMI_AUDIO_INFOFRAME_SIZE) {
> @@ -1151,8 +1163,9 @@ static int hdmi_audio_infoframe_unpack(struct hdmi_audio_infoframe *frame,
>  
>  /**
>   * hdmi_vendor_infoframe_unpack() - unpack binary buffer to a HDMI vendor infoframe
> - * @buffer: source buffer
>   * @frame: HDMI Vendor infoframe
> + * @buffer: source buffer
> + * @size: size of buffer
>   *
>   * Unpacks the information contained in binary @buffer into a structured
>   * @frame of the HDMI Vendor information frame.
> @@ -1163,7 +1176,7 @@ static int hdmi_audio_infoframe_unpack(struct hdmi_audio_infoframe *frame,
>   */
>  static int
>  hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
> -				 const void *buffer)
> +				 const void *buffer, size_t size)
>  {
>  	const u8 *ptr = buffer;
>  	size_t length;
> @@ -1171,6 +1184,9 @@ hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
>  	u8 hdmi_video_format;
>  	struct hdmi_vendor_infoframe *hvf = &frame->hdmi;
>  
> +	if (size < HDMI_INFOFRAME_HEADER_SIZE)
> +		return -EINVAL;
> +

This check is not needed since that is already done in hdmi_infoframe_unpack().

>  	if (ptr[0] != HDMI_INFOFRAME_TYPE_VENDOR ||
>  	    ptr[1] != 1 ||
>  	    (ptr[2] != 4 && ptr[2] != 5 && ptr[2] != 6))
> @@ -1178,6 +1194,9 @@ hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
>  
>  	length = ptr[2];
>  
> +	if (size < HDMI_INFOFRAME_HEADER_SIZE + length)
> +		return -EINVAL;
> +
>  	if (hdmi_infoframe_checksum(buffer,
>  				    HDMI_INFOFRAME_HEADER_SIZE + length) != 0)
>  		return -EINVAL;
> @@ -1224,8 +1243,9 @@ hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
>  
>  /**
>   * hdmi_infoframe_unpack() - unpack binary buffer to a HDMI infoframe
> - * @buffer: source buffer
>   * @frame: HDMI infoframe
> + * @buffer: source buffer
> + * @size: size of buffer
>   *
>   * Unpacks the information contained in binary buffer @buffer into a structured
>   * @frame of a HDMI infoframe.
> @@ -1235,23 +1255,26 @@ hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
>   * Returns 0 on success or a negative error code on failure.
>   */
>  int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
> -			  const void *buffer)
> +			  const void *buffer, size_t size)
>  {
>  	int ret;
>  	const u8 *ptr = buffer;
>  
> +	if (size < HDMI_INFOFRAME_HEADER_SIZE)
> +		return -EINVAL;
> +
>  	switch (ptr[0]) {
>  	case HDMI_INFOFRAME_TYPE_AVI:
> -		ret = hdmi_avi_infoframe_unpack(&frame->avi, buffer);
> +		ret = hdmi_avi_infoframe_unpack(&frame->avi, buffer, size);
>  		break;
>  	case HDMI_INFOFRAME_TYPE_SPD:
> -		ret = hdmi_spd_infoframe_unpack(&frame->spd, buffer);
> +		ret = hdmi_spd_infoframe_unpack(&frame->spd, buffer, size);
>  		break;
>  	case HDMI_INFOFRAME_TYPE_AUDIO:
> -		ret = hdmi_audio_infoframe_unpack(&frame->audio, buffer);
> +		ret = hdmi_audio_infoframe_unpack(&frame->audio, buffer, size);
>  		break;
>  	case HDMI_INFOFRAME_TYPE_VENDOR:
> -		ret = hdmi_vendor_any_infoframe_unpack(&frame->vendor, buffer);
> +		ret = hdmi_vendor_any_infoframe_unpack(&frame->vendor, buffer, size);
>  		break;
>  	default:
>  		ret = -EINVAL;
> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
> index d3816170c062..a577d4ae2570 100644
> --- a/include/linux/hdmi.h
> +++ b/include/linux/hdmi.h
> @@ -333,7 +333,7 @@ union hdmi_infoframe {
>  ssize_t
>  hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size);
>  int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
> -			  const void *buffer);
> +			  const void *buffer, size_t size);
>  void hdmi_infoframe_log(const char *level, struct device *dev,
>  			union hdmi_infoframe *frame);
>  
> 

FYI: I'll be posting two other hdmi.c patches today that we (Cisco) have in our queue
for some time.

Regards,

	Hans


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