Re: [PATCH 02/18] video/hdmi: Pass buffer size to infoframe unpack functions

Hans Verkuil
2018-09-21T08:06:20Z

On 09/20/18 20:51, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@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.
>
> v2: Convert tda1997x.c as well (kbuild test robot)
>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Hans Verkuil <hans.verkuil@cisco.com>

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Thanks,

Hans

> Cc: linux-media@vger.kernel.org
> Signed-off-by: Ville Syrjälä <ville.syrjala@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/media/i2c/tda1997x.c | 4 ++--
> drivers/video/hdmi.c | 51 ++++++++++++++++++++++++++++++++------------
> include/linux/hdmi.h | 2 +-
> 7 files changed, 44 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/media/i2c/adv7511.c b/drivers/media/i2c/adv7511.c
> index 55c2ea0720d9..b85b181bbb6c 100644
> --- a/drivers/media/i2c/adv7511.c
> +++ b/drivers/media/i2c/adv7511.c
> @@ -550,7 +550,7 @@ 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 668be2bca57a..2e7a28dbad4e 100644
> --- a/drivers/media/i2c/adv7604.c
> +++ b/drivers/media/i2c/adv7604.c
> @@ -2418,7 +2418,7 @@ 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 4f8fbdd00e35..2cfd03f929b2 100644
> --- a/drivers/media/i2c/adv7842.c
> +++ b/drivers/media/i2c/adv7842.c
> @@ -2563,7 +2563,7 @@ 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 44c41933415a..519bf92508d5 100644
> --- a/drivers/media/i2c/tc358743.c
> +++ b/drivers/media/i2c/tc358743.c
> @@ -444,7 +444,7 @@ 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/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c
> index d114ac5243ec..195a1fc74ee8 100644
> --- a/drivers/media/i2c/tda1997x.c
> +++ b/drivers/media/i2c/tda1997x.c
> @@ -1253,7 +1253,7 @@ tda1997x_parse_infoframe(struct tda1997x_state *state, u16 addr)
>
> /* read data */
> len = io_readn(sd, addr, sizeof(buffer), buffer);
> - err = hdmi_infoframe_unpack(&frame, buffer);
> + err = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer));
> if (err) {
> v4l_err(state->client,
> "failed parsing %d byte infoframe: 0x%04x/0x%02x\n",
> @@ -1928,7 +1928,7 @@ static int tda1997x_log_infoframe(struct v4l2_subdev *sd, int addr)
> /* read data */
> len = io_readn(sd, addr, sizeof(buffer), buffer);
> v4l2_dbg(1, debug, sd, "infoframe: addr=%d len=%d\n", addr, len);
> - err = hdmi_infoframe_unpack(&frame, buffer);
> + err = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer));
> if (err) {
> v4l_err(state->client,
> "failed parsing %d byte infoframe: 0x%04x/0x%02x\n",
> 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;
> +
> 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);