[xine-cvs] HG: xine-lib: Add allocation checks to the Real MDPR parsing code (ref. CVE-2008-5240).

[Darren S. <li...@yo...>]

# HG changeset patch
# User Darren Salt <li...@yo...>
# Date 1232291432 0
# Node ID 071dc93156e6940a7f1b8bb38762d521dd5731e8
# Parent  aed53c8313f0d3cb91073bc61e45000133444c91
Add allocation checks to the Real MDPR parsing code (ref. CVE-2008-5240).

diff -r 071dc93156e6940a7f1b8bb38762d521dd5731e8 -r aed53c8313f0d3cb91073bc61e45000133444c91 src/demuxers/demux_real.c
--- a/src/demuxers/demux_real.c	Sun Jan 18 15:10:32 2009 +0000
+++ b/src/demuxers/demux_real.c	Sun Jan 18 02:31:06 2009 +0000
@@ -265,8 +265,12 @@ static void real_parse_index(demux_real_
   this->input->seek(this->input, original_pos, SEEK_SET);
 }
 
-static mdpr_t *real_parse_mdpr(const char *data) {
-  mdpr_t *mdpr=malloc(sizeof(mdpr_t));
+static mdpr_t *real_parse_mdpr(const char *data, const unsigned int size)
+{
+  if (size < 38)
+    return NULL;
+
+  mdpr_t *mdpr=calloc(sizeof(mdpr_t), 1);
 
   mdpr->stream_number=_X_BE_16(&data[2]);
   mdpr->max_bit_rate=_X_BE_32(&data[4]);
@@ -278,17 +282,29 @@ static mdpr_t *real_parse_mdpr(const cha
   mdpr->duration=_X_BE_32(&data[28]);
 
   mdpr->stream_name_size=data[32];
+  if (size < 38 + mdpr->stream_name_size)
+    goto fail;
   mdpr->stream_name=malloc(mdpr->stream_name_size+1);
+  if (!mdpr->stream_name)
+    goto fail;
   memcpy(mdpr->stream_name, &data[33], mdpr->stream_name_size);
   mdpr->stream_name[(int)mdpr->stream_name_size]=0;
 
   mdpr->mime_type_size=data[33+mdpr->stream_name_size];
+  if (size < 38 + mdpr->stream_name_size + mdpr->mime_type_size)
+    goto fail;
   mdpr->mime_type=malloc(mdpr->mime_type_size+1);
+  if (!mdpr->mime_type)
+    goto fail;
   memcpy(mdpr->mime_type, &data[34+mdpr->stream_name_size], mdpr->mime_type_size);
   mdpr->mime_type[(int)mdpr->mime_type_size]=0;
 
   mdpr->type_specific_len=_X_BE_32(&data[34+mdpr->stream_name_size+mdpr->mime_type_size]);
+  if (size < 38 + mdpr->stream_name_size + mdpr->mime_type_size + mdpr->type_specific_data)
+    goto fail;
   mdpr->type_specific_data=malloc(mdpr->type_specific_len);
+  if (!mdpr->type_specific_data)
+    goto fail;
   memcpy(mdpr->type_specific_data,
       &data[38+mdpr->stream_name_size+mdpr->mime_type_size], mdpr->type_specific_len);
 
@@ -308,6 +324,13 @@ static mdpr_t *real_parse_mdpr(const cha
 #endif
 
   return mdpr;
+
+fail:
+  free (mdpr->stream_name);
+  free (mdpr->mime_type);
+  free (mdpr->type_specific_data);
+  free (mdpr);
+  return NULL;
 }
 
 static void real_free_mdpr (mdpr_t *mdpr) {
@@ -491,9 +514,14 @@ static void real_parse_headers (demux_re
 	    continue;
 	  }
                 
-	  mdpr_t *const mdpr = real_parse_mdpr (chunk_buffer);
+	  mdpr_t *const mdpr = real_parse_mdpr (chunk_buffer, chunk_size);
 
 	  lprintf ("parsing type specific data...\n");
+	  if (!mdpr) {
+	    free (chunk_buffer);
+	    this->status = DEMUX_FINISHED;
+	    return;
+	  }
 	  if(!strcmp(mdpr->mime_type, "audio/X-MP3-draft-00")) {
 	    lprintf ("mpeg layer 3 audio detected...\n");
 
diff -r 071dc93156e6940a7f1b8bb38762d521dd5731e8 -r aed53c8313f0d3cb91073bc61e45000133444c91 src/input/libreal/rmff.c
--- a/src/input/libreal/rmff.c	Sun Jan 18 15:10:32 2009 +0000
+++ b/src/input/libreal/rmff.c	Sun Jan 18 02:31:06 2009 +0000
@@ -334,12 +334,14 @@ static rmff_prop_t *rmff_scan_prop(const
   return prop;
 }
 
-static rmff_mdpr_t *rmff_scan_mdpr(const char *data) {
-
-  rmff_mdpr_t *mdpr = malloc(sizeof(rmff_mdpr_t));
+static rmff_mdpr_t *rmff_scan_mdpr(const char *data)
+{
+  rmff_mdpr_t *mdpr = calloc(sizeof(rmff_mdpr_t), 1);
 
   mdpr->object_id=_X_BE_32(data);
   mdpr->size=_X_BE_32(&data[4]);
+  if (mdpr->size < 46)
+    goto fail;
   mdpr->object_version=_X_BE_16(&data[8]);
   if (mdpr->object_version != 0)
   {
@@ -355,21 +357,40 @@ static rmff_mdpr_t *rmff_scan_mdpr(const
   mdpr->duration=_X_BE_32(&data[36]);
   
   mdpr->stream_name_size=data[40];
+  if (mdpr->size < 46 + mdpr->stream_name_size)
+    goto fail;
   mdpr->stream_name = malloc(mdpr->stream_name_size+1);
+  if (!mdpr->stream_name)
+    goto fail;
   memcpy(mdpr->stream_name, &data[41], mdpr->stream_name_size);
   mdpr->stream_name[mdpr->stream_name_size]=0;
   
   mdpr->mime_type_size=data[41+mdpr->stream_name_size];
+  if (mdpr->size < 46 + mdpr->stream_name_size + mdpr->mime_type_size)
+    goto fail;
   mdpr->mime_type = malloc(mdpr->mime_type_size+1);
+  if (!mdpr->mime_type)
+    goto fail;
   memcpy(mdpr->mime_type, &data[42+mdpr->stream_name_size], mdpr->mime_type_size);
   mdpr->mime_type[mdpr->mime_type_size]=0;
   
   mdpr->type_specific_len=_X_BE_32(&data[42+mdpr->stream_name_size+mdpr->mime_type_size]);
+  if (mdpr->size < 46 + mdpr->stream_name_size + mdpr->mime_type_size + mdpr->type_specific_data)
+    goto fail;
   mdpr->type_specific_data = malloc(mdpr->type_specific_len);
+  if (!mdpr->type_specific_data)
+    goto fail;
   memcpy(mdpr->type_specific_data, 
       &data[46+mdpr->stream_name_size+mdpr->mime_type_size], mdpr->type_specific_len);
   
   return mdpr;
+
+fail:
+  free (mdpr->stream_name);
+  free (mdpr->mime_type);
+  free (mdpr->type_specific_data);
+  free (mdpr);
+  return NULL;
 }
 
 static rmff_cont_t *rmff_scan_cont(const char *data) {
@@ -467,8 +488,11 @@ rmff_header_t *rmff_scan_header(const ch
       break;
     case MDPR_TAG:
       mdpr=rmff_scan_mdpr(ptr);
-      chunk_size=mdpr->size;
-      header->streams[mdpr->stream_number]=mdpr;
+      if (mdpr) /* FIXME: what to do if NULL? */
+      {
+        chunk_size=mdpr->size;
+        header->streams[mdpr->stream_number]=mdpr;
+      }
       break;
     case CONT_TAG:
       header->cont=rmff_scan_cont(ptr);