From d5caac8ab79d068ad9a41030c772d03a4d4fbd7b Mon Sep 17 00:00:00 2001

From: Daniel Axtens <dja@axtens.net>

Date: Mon, 28 Jun 2021 14:16:14 +1000

Subject: [PATCH 5/8] video/readers/jpeg: Abort sooner if a read operation

 fails

Fuzzing revealed some inputs that were taking a long time, potentially

forever, because they did not bail quickly upon encountering an I/O error.

Try to catch I/O errors sooner and bail out.

Signed-off-by: Daniel Axtens <dja@axtens.net>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

---

 grub-core/video/readers/jpeg.c | 86 +++++++++++++++++++++++++++-------

 1 file changed, 70 insertions(+), 16 deletions(-)

diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c

index c47ffd651..806c56c78 100644

--- a/grub-core/video/readers/jpeg.c

+++ b/grub-core/video/readers/jpeg.c

@@ -109,9 +109,17 @@ static grub_uint8_t

 grub_jpeg_get_byte (struct grub_jpeg_data *data)

 {

   grub_uint8_t r;

+  grub_ssize_t bytes_read;

   r = 0;

-  grub_file_read (data->file, &r, 1);

+  bytes_read = grub_file_read (data->file, &r, 1);

+

+  if (bytes_read != 1)

+    {

+      grub_error (GRUB_ERR_BAD_FILE_TYPE,

+		  "jpeg: unexpected end of data");

+      return 0;

+    }

   return r;

 }

@@ -120,9 +128,17 @@ static grub_uint16_t

 grub_jpeg_get_word (struct grub_jpeg_data *data)

 {

   grub_uint16_t r;

+  grub_ssize_t bytes_read;

   r = 0;

-  grub_file_read (data->file, &r, sizeof (grub_uint16_t));

+  bytes_read = grub_file_read (data->file, &r, sizeof (grub_uint16_t));

+

+  if (bytes_read != sizeof (grub_uint16_t))

+    {

+      grub_error (GRUB_ERR_BAD_FILE_TYPE,

+		  "jpeg: unexpected end of data");

+      return 0;

+    }

   return grub_be_to_cpu16 (r);

 }

@@ -135,6 +151,11 @@ grub_jpeg_get_bit (struct grub_jpeg_data *data)

   if (data->bit_mask == 0)

     {

       data->bit_save = grub_jpeg_get_byte (data);

+      if (grub_errno != GRUB_ERR_NONE) {

+	grub_error (GRUB_ERR_BAD_FILE_TYPE,

+		    "jpeg: file read error");

+	return 0;

+      }

       if (data->bit_save == JPEG_ESC_CHAR)

 	{

 	  if (grub_jpeg_get_byte (data) != 0)

@@ -143,6 +164,11 @@ grub_jpeg_get_bit (struct grub_jpeg_data *data)

 			  "jpeg: invalid 0xFF in data stream");

 	      return 0;

 	    }

+	  if (grub_errno != GRUB_ERR_NONE)

+	    {

+	      grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: file read error");

+	      return 0;

+	    }

 	}

       data->bit_mask = 0x80;

     }

@@ -161,7 +187,7 @@ grub_jpeg_get_number (struct grub_jpeg_data *data, int num)

     return 0;

   msb = value = grub_jpeg_get_bit (data);

-  for (i = 1; i < num; i++)

+  for (i = 1; i < num && grub_errno == GRUB_ERR_NONE; i++)

     value = (value << 1) + (grub_jpeg_get_bit (data) != 0);

   if (!msb)

     value += 1 - (1 << num);

@@ -208,6 +234,8 @@ grub_jpeg_decode_huff_table (struct grub_jpeg_data *data)

   while (data->file->offset + sizeof (count) + 1 <= next_marker)

     {

       id = grub_jpeg_get_byte (data);

+      if (grub_errno != GRUB_ERR_NONE)

+	return grub_errno;

       ac = (id >> 4) & 1;

       id &= 0xF;

       if (id > 1)

@@ -258,6 +286,8 @@ grub_jpeg_decode_quan_table (struct grub_jpeg_data *data)

   next_marker = data->file->offset;

   next_marker += grub_jpeg_get_word (data);

+  if (grub_errno != GRUB_ERR_NONE)

+    return grub_errno;

   if (next_marker > data->file->size)

     {

@@ -269,6 +299,8 @@ grub_jpeg_decode_quan_table (struct grub_jpeg_data *data)

 	 <= next_marker)

     {

       id = grub_jpeg_get_byte (data);

+      if (grub_errno != GRUB_ERR_NONE)

+        return grub_errno;

       if (id >= 0x10)		/* Upper 4-bit is precision.  */

 	return grub_error (GRUB_ERR_BAD_FILE_TYPE,

 			   "jpeg: only 8-bit precision is supported");

@@ -300,6 +332,9 @@ grub_jpeg_decode_sof (struct grub_jpeg_data *data)

   next_marker = data->file->offset;

   next_marker += grub_jpeg_get_word (data);

+  if (grub_errno != GRUB_ERR_NONE)

+    return grub_errno;

+

   if (grub_jpeg_get_byte (data) != 8)

     return grub_error (GRUB_ERR_BAD_FILE_TYPE,

 		       "jpeg: only 8-bit precision is supported");

@@ -325,6 +360,8 @@ grub_jpeg_decode_sof (struct grub_jpeg_data *data)

 	return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid index");

       ss = grub_jpeg_get_byte (data);	/* Sampling factor.  */

+      if (grub_errno != GRUB_ERR_NONE)

+	return grub_errno;

       if (!id)

 	{

 	  grub_uint8_t vs, hs;

@@ -504,7 +541,7 @@ grub_jpeg_idct_transform (jpeg_data_unit_t du)

     }

 }

-static void

+static grub_err_t

 grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du)

 {

   int h1, h2, qt;

@@ -519,6 +556,9 @@ grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du)

   data->dc_value[id] +=

     grub_jpeg_get_number (data, grub_jpeg_get_huff_code (data, h1));

+  if (grub_errno != GRUB_ERR_NONE)

+    return grub_errno;

+

   du[0] = data->dc_value[id] * (int) data->quan_table[qt][0];

   pos = 1;

   while (pos < ARRAY_SIZE (data->quan_table[qt]))

@@ -533,11 +573,13 @@ grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du)

       num >>= 4;

       pos += num;

+      if (grub_errno != GRUB_ERR_NONE)

+        return grub_errno;

+

       if (pos >= ARRAY_SIZE (jpeg_zigzag_order))

 	{

-	  grub_error (GRUB_ERR_BAD_FILE_TYPE,

-		      "jpeg: invalid position in zigzag order!?");

-	  return;

+	  return grub_error (GRUB_ERR_BAD_FILE_TYPE,

+			     "jpeg: invalid position in zigzag order!?");

 	}

       du[jpeg_zigzag_order[pos]] = val * (int) data->quan_table[qt][pos];

@@ -545,6 +587,7 @@ grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du)

     }

   grub_jpeg_idct_transform (du);

+  return GRUB_ERR_NONE;

 }

 static void

@@ -603,7 +646,8 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data)

   data_offset += grub_jpeg_get_word (data);

   cc = grub_jpeg_get_byte (data);

-

+  if (grub_errno != GRUB_ERR_NONE)

+    return grub_errno;

   if (cc != 3 && cc != 1)

     return grub_error (GRUB_ERR_BAD_FILE_TYPE,

 		       "jpeg: component count must be 1 or 3");

@@ -616,7 +660,8 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data)

       id = grub_jpeg_get_byte (data) - 1;

       if ((id < 0) || (id >= 3))

 	return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid index");

-

+      if (grub_errno != GRUB_ERR_NONE)

+	return grub_errno;

       ht = grub_jpeg_get_byte (data);

       data->comp_index[id][1] = (ht >> 4);

       data->comp_index[id][2] = (ht & 0xF) + 2;

@@ -624,11 +669,14 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data)

       if ((data->comp_index[id][1] < 0) || (data->comp_index[id][1] > 3) ||

 	  (data->comp_index[id][2] < 0) || (data->comp_index[id][2] > 3))

 	return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid hufftable index");

+      if (grub_errno != GRUB_ERR_NONE)

+	return grub_errno;

     }

   grub_jpeg_get_byte (data);	/* Skip 3 unused bytes.  */

   grub_jpeg_get_word (data);

-

+  if (grub_errno != GRUB_ERR_NONE)

+    return grub_errno;

   if (data->file->offset != data_offset)

     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: extra byte in sos");

@@ -646,6 +694,7 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data)

 {

   unsigned c1, vb, hb, nr1, nc1;

   int rst = data->dri;

+  grub_err_t err = GRUB_ERR_NONE;

   vb = 8 << data->log_vs;

   hb = 8 << data->log_hs;

@@ -666,17 +715,22 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data)

 	for (r2 = 0; r2 < (1U << data->log_vs); r2++)

 	  for (c2 = 0; c2 < (1U << data->log_hs); c2++)

-	    grub_jpeg_decode_du (data, 0, data->ydu[r2 * 2 + c2]);

+            {

+              err = grub_jpeg_decode_du (data, 0, data->ydu[r2 * 2 + c2]);

+              if (err != GRUB_ERR_NONE)

+                return err;

+            }

 	if (data->color_components >= 3)

 	  {

-	    grub_jpeg_decode_du (data, 1, data->cbdu);

-	    grub_jpeg_decode_du (data, 2, data->crdu);

+	    err = grub_jpeg_decode_du (data, 1, data->cbdu);

+	    if (err != GRUB_ERR_NONE)

+	      return err;

+	    err = grub_jpeg_decode_du (data, 2, data->crdu);

+	    if (err != GRUB_ERR_NONE)

+	      return err;

 	  }

-	if (grub_errno)

-	  return grub_errno;

-

 	nr2 = (data->r1 == nr1 - 1) ? (data->image_height - data->r1 * vb) : vb;

 	nc2 = (c1 == nc1 - 1) ? (data->image_width - c1 * hb) : hb;

-- 

2.33.5