extra checking on memory allocation sizes to prevent a class of overflow attacks
diff --git a/src/libFLAC/metadata_object.c b/src/libFLAC/metadata_object.c
index 3cfe89c..9a6b5d2 100644
--- a/src/libFLAC/metadata_object.c
+++ b/src/libFLAC/metadata_object.c
@@ -39,6 +39,7 @@
#include "private/metadata.h"
#include "FLAC/assert.h"
+#include "share/alloc.h"
/****************************************************************************
@@ -53,14 +54,14 @@
* from != NULL && bytes > 0
* to <- copy of from
* else ASSERT
- * malloc error leaved 'to' unchanged
+ * malloc error leaves 'to' unchanged
*/
static FLAC__bool copy_bytes_(FLAC__byte **to, const FLAC__byte *from, unsigned bytes)
{
FLAC__ASSERT(0 != to);
if(bytes > 0 && 0 != from) {
FLAC__byte *x;
- if(0 == (x = (FLAC__byte*)malloc(bytes)))
+ if(0 == (x = (FLAC__byte*)safe_malloc_(bytes)))
return false;
memcpy(x, from, bytes);
*to = x;
@@ -94,7 +95,7 @@
/* realloc() failure leaves entry unchanged */
static FLAC__bool ensure_null_terminated_(FLAC__byte **entry, unsigned length)
{
- FLAC__byte *x = (FLAC__byte*)realloc(*entry, length+1);
+ FLAC__byte *x = (FLAC__byte*)safe_realloc_add_2op_(*entry, length, /*+*/1);
if(0 != x) {
x[length] = '\0';
*entry = x;
@@ -132,7 +133,7 @@
else {
FLAC__byte *x;
FLAC__ASSERT(from->length > 0);
- if(0 == (x = (FLAC__byte*)malloc(from->length+1)))
+ if(0 == (x = (FLAC__byte*)safe_malloc_add_2op_(from->length, /*+*/1)))
return false;
memcpy(x, from->entry, from->length);
x[from->length] = '\0';
@@ -150,7 +151,7 @@
else {
FLAC__StreamMetadata_CueSheet_Index *x;
FLAC__ASSERT(from->num_indices > 0);
- if(0 == (x = (FLAC__StreamMetadata_CueSheet_Index*)malloc(from->num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index))))
+ if(0 == (x = (FLAC__StreamMetadata_CueSheet_Index*)safe_malloc_mul_2op_(from->num_indices, /*times*/sizeof(FLAC__StreamMetadata_CueSheet_Index))))
return false;
memcpy(x, from->indices, from->num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index));
to->indices = x;
@@ -172,7 +173,7 @@
FLAC__ASSERT(num_points > 0);
- object_array = (FLAC__StreamMetadata_SeekPoint*)malloc(num_points * sizeof(FLAC__StreamMetadata_SeekPoint));
+ object_array = (FLAC__StreamMetadata_SeekPoint*)safe_malloc_mul_2op_(num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint));
if(0 != object_array) {
unsigned i;
@@ -205,7 +206,7 @@
{
FLAC__ASSERT(num_comments > 0);
- return (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry));
+ return (FLAC__StreamMetadata_VorbisComment_Entry*)safe_calloc_(num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry));
}
static void vorbiscomment_entry_array_delete_(FLAC__StreamMetadata_VorbisComment_Entry *object_array, unsigned num_comments)
@@ -344,14 +345,14 @@
{
FLAC__ASSERT(num_indices > 0);
- return (FLAC__StreamMetadata_CueSheet_Index*)calloc(num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index));
+ return (FLAC__StreamMetadata_CueSheet_Index*)safe_calloc_(num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index));
}
static FLAC__StreamMetadata_CueSheet_Track *cuesheet_track_array_new_(unsigned num_tracks)
{
FLAC__ASSERT(num_tracks > 0);
- return (FLAC__StreamMetadata_CueSheet_Track*)calloc(num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track));
+ return (FLAC__StreamMetadata_CueSheet_Track*)safe_calloc_(num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track));
}
static void cuesheet_track_array_delete_(FLAC__StreamMetadata_CueSheet_Track *object_array, unsigned num_tracks)
@@ -537,6 +538,10 @@
case FLAC__METADATA_TYPE_PADDING:
break;
case FLAC__METADATA_TYPE_APPLICATION:
+ if(to->length < FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8) { /* underflow check */
+ FLAC__metadata_object_delete(to);
+ return 0;
+ }
memcpy(&to->data.application.id, &object->data.application.id, FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8);
if(!copy_bytes_(&to->data.application.data, object->data.application.data, object->length - FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8)) {
FLAC__metadata_object_delete(to);
@@ -545,6 +550,10 @@
break;
case FLAC__METADATA_TYPE_SEEKTABLE:
to->data.seek_table.num_points = object->data.seek_table.num_points;
+ if(to->data.seek_table.num_points > SIZE_MAX / sizeof(FLAC__StreamMetadata_SeekPoint)) { /* overflow check */
+ FLAC__metadata_object_delete(to);
+ return 0;
+ }
if(!copy_bytes_((FLAC__byte**)&to->data.seek_table.points, (FLAC__byte*)object->data.seek_table.points, object->data.seek_table.num_points * sizeof(FLAC__StreamMetadata_SeekPoint))) {
FLAC__metadata_object_delete(to);
return 0;
@@ -930,8 +939,12 @@
return false;
}
else {
- const unsigned old_size = object->data.seek_table.num_points * sizeof(FLAC__StreamMetadata_SeekPoint);
- const unsigned new_size = new_num_points * sizeof(FLAC__StreamMetadata_SeekPoint);
+ const size_t old_size = object->data.seek_table.num_points * sizeof(FLAC__StreamMetadata_SeekPoint);
+ const size_t new_size = new_num_points * sizeof(FLAC__StreamMetadata_SeekPoint);
+
+ /* overflow check */
+ if((size_t)new_num_points > SIZE_MAX / sizeof(FLAC__StreamMetadata_SeekPoint))
+ return false;
FLAC__ASSERT(object->data.seek_table.num_points > 0);
@@ -1157,8 +1170,12 @@
return false;
}
else {
- const unsigned old_size = object->data.vorbis_comment.num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry);
- const unsigned new_size = new_num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry);
+ const size_t old_size = object->data.vorbis_comment.num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry);
+ const size_t new_size = new_num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry);
+
+ /* overflow check */
+ if((size_t)new_num_comments > SIZE_MAX / sizeof(FLAC__StreamMetadata_VorbisComment_Entry))
+ return false;
FLAC__ASSERT(object->data.vorbis_comment.num_comments > 0);
@@ -1306,7 +1323,7 @@
const size_t nn = strlen(field_name);
const size_t nv = strlen(field_value);
entry->length = nn + 1 /*=*/ + nv;
- if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length+1)))
+ if(0 == (entry->entry = (FLAC__byte*)safe_malloc_add_4op_(nn, /*+*/1, /*+*/nv, /*+*/1)))
return false;
memcpy(entry->entry, field_name, nn);
entry->entry[nn] = '=';
@@ -1333,9 +1350,9 @@
FLAC__ASSERT(0 != eq);
if(0 == eq)
return false; /* double protection */
- if(0 == (*field_name = (char*)malloc(nn+1)))
+ if(0 == (*field_name = (char*)safe_malloc_add_2op_(nn, /*+*/1)))
return false;
- if(0 == (*field_value = (char*)malloc(nv+1))) {
+ if(0 == (*field_value = (char*)safe_malloc_add_2op_(nv, /*+*/1))) {
free(*field_name);
return false;
}
@@ -1465,8 +1482,12 @@
return false;
}
else {
- const unsigned old_size = track->num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index);
- const unsigned new_size = new_num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index);
+ const size_t old_size = track->num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index);
+ const size_t new_size = new_num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index);
+
+ /* overflow check */
+ if((size_t)new_num_indices > SIZE_MAX / sizeof(FLAC__StreamMetadata_CueSheet_Index))
+ return false;
FLAC__ASSERT(track->num_indices > 0);
@@ -1549,8 +1570,12 @@
return false;
}
else {
- const unsigned old_size = object->data.cue_sheet.num_tracks * sizeof(FLAC__StreamMetadata_CueSheet_Track);
- const unsigned new_size = new_num_tracks * sizeof(FLAC__StreamMetadata_CueSheet_Track);
+ const size_t old_size = object->data.cue_sheet.num_tracks * sizeof(FLAC__StreamMetadata_CueSheet_Track);
+ const size_t new_size = new_num_tracks * sizeof(FLAC__StreamMetadata_CueSheet_Track);
+
+ /* overflow check */
+ if((size_t)new_num_tracks > SIZE_MAX / sizeof(FLAC__StreamMetadata_CueSheet_Track))
+ return false;
FLAC__ASSERT(object->data.cue_sheet.num_tracks > 0);
@@ -1707,6 +1732,8 @@
/* do the copy first so that if we fail we leave the object untouched */
if(copy) {
+ if(new_length >= SIZE_MAX) /* overflow check */
+ return false;
if(!copy_bytes_((FLAC__byte**)(&object->data.picture.mime_type), (FLAC__byte*)mime_type, new_length+1))
return false;
}
@@ -1737,6 +1764,8 @@
/* do the copy first so that if we fail we leave the object untouched */
if(copy) {
+ if(new_length >= SIZE_MAX) /* overflow check */
+ return false;
if(!copy_bytes_(&object->data.picture.description, description, new_length+1))
return false;
}