blender
/
blender
129
398
Fork 572
Code Issues 6.2k Pull Requests 747 Projects 19 Wiki Activity

readfile: skip negative sized thumbnails 

We may want to use 'TEST' BCode in the future for including data
besides thumbnails. This allows negative values to be used w/o
attempting to load a thumbnail.
This commit is contained in:
Campbell Barton 2019-02-11 19:09:27 +11:00
parent 3ce5e5a857
commit 1724ff29e0
2 changed files with 15 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
source/blender/blenkernel/BKE_main.h
View File

@ -169,8 +169,12 @@ int set_listbasepointers(struct Main *main, struct ListBase *lb[MAX_LIBARRAY]);
#define BLEN_THUMB_SIZE 128
#define BLEN_THUMB_MEMSIZE(_x, _y) (sizeof(BlendThumbnail) + ((size_t)(_x) * (size_t)(_y)) * sizeof(int))
#define BLEN_THUMB_SAFE_MEMSIZE(_x, _y) ((uint64_t)_x * (uint64_t)_y < (SIZE_MAX / (sizeof(int) * 4)))
#define BLEN_THUMB_MEMSIZE(_x, _y) \
(sizeof(BlendThumbnail) + ((size_t)(_x) * (size_t)(_y)) * sizeof(int))
/** Protect against buffer overflow vulnerability & negative sizes. */
#define BLEN_THUMB_MEMSIZE_IS_VALID(_x, _y) \
(((_x) > 0 && (_y) > 0) && \
((uint64_t)(_x) * (uint64_t)(_y) < (SIZE_MAX / (sizeof(int) * 4))))
#ifdef __cplusplus
}

24
source/blender/blenloader/intern/readfile.c
View File

@ -977,10 +977,9 @@ static int *read_file_thumbnail(FileData *fd)
BLI_endian_switch_int32(&data[1]);
}
int width = data[0];
int height = data[1];
if (!BLEN_THUMB_SAFE_MEMSIZE(width, height)) {
const int width = data[0];
const int height = data[1];
if (!BLEN_THUMB_MEMSIZE_IS_VALID(width, height)) {
break;
}
if (bhead->len < BLEN_THUMB_MEMSIZE_FILE(width, height)) {
@ -1422,14 +1421,11 @@ BlendThumbnail *BLO_thumbnail_from_file(const char *filepath)
fd_data = fd ? read_file_thumbnail(fd) : NULL;
if (fd_data) {
int width = fd_data[0];
int height = fd_data[1];
/* Protect against buffer overflow vulnerability. */
if (BLEN_THUMB_SAFE_MEMSIZE(width, height)) {
const int width = fd_data[0];
const int height = fd_data[1];
if (BLEN_THUMB_MEMSIZE_IS_VALID(width, height)) {
const size_t sz = BLEN_THUMB_MEMSIZE(width, height);
data = MEM_mallocN(sz, __func__);
if (data) {
BLI_assert((sz - sizeof(*data)) == (BLEN_THUMB_MEMSIZE_FILE(width, height) - (sizeof(*fd_data) * 2)));
data->width = width;
@ -8997,11 +8993,9 @@ BlendFileData *blo_read_file_internal(FileData *fd, const char *filepath)
const int *data = read_file_thumbnail(fd);
if (data) {
int width = data[0];
int height = data[1];
/* Protect against buffer overflow vulnerability. */
if (BLEN_THUMB_SAFE_MEMSIZE(width, height)) {
const int width = data[0];
const int height = data[1];
if (BLEN_THUMB_MEMSIZE_IS_VALID(width, height)) {
const size_t sz = BLEN_THUMB_MEMSIZE(width, height);
bfd->main->blen_thumb = MEM_mallocN(sz, __func__);