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

[Ville Syrjala <ville.syrjala@linux.intel.com>]

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>
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);
 
-- 
2.16.4