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TiffDec: enforce stricter mem/dimension limit on tiles

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Tile can be even larger than image dimensions.

Change-Id: I80518e815bb11d7a07c8189d0493b3cc60e29815
This commit is contained in:
Skal 2021-01-12 09:55:47 +01:00
parent 8696147da4
commit 289757fe1e
3 changed files with 31 additions and 19 deletions
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6
imageio/imageio_util.c
View File

@ -148,9 +148,11 @@ void ImgIoUtilCopyPlane(const uint8_t* src, int src_stride,
// -----------------------------------------------------------------------------
int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
const uint64_t total_size = nmemb * size;
int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t stride, size_t height) {
const uint64_t total_size = stride * height;
int ok = (total_size == (size_t)total_size);
// check that 'stride' is representable as int:
ok = ok && ((uint64_t)(int)stride == stride);
#if defined(WEBP_MAX_IMAGE_SIZE)
ok = ok && (total_size <= (uint64_t)WEBP_MAX_IMAGE_SIZE);
#endif

4
imageio/imageio_util.h
View File

@ -54,8 +54,8 @@ void ImgIoUtilCopyPlane(const uint8_t* src, int src_stride,
//------------------------------------------------------------------------------
// Returns 0 in case of overflow of nmemb * size.
int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t nmemb, size_t size);
// Returns 0 in case of overflow, memory over-allocation or excessive dimension.
int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t stride, size_t height);
#ifdef __cplusplus
} // extern "C"

40
imageio/tiffdec.c
View File

@ -157,6 +157,7 @@ int ReadTIFF(const uint8_t* const data, size_t data_size,
MyData my_data = { data, (toff_t)data_size, 0 };
TIFF* tif;
uint32_t image_width, image_height, tile_width, tile_height;
uint64_t stride;
uint16_t samples_per_px = 0;
uint16_t extra_samples = 0;
uint16_t* extra_samples_ptr = NULL;
@ -194,20 +195,31 @@ int ReadTIFF(const uint8_t* const data, size_t data_size,
fprintf(stderr, "Error! Cannot retrieve TIFF image dimensions.\n");
goto End;
}
if (!ImgIoUtilCheckSizeArgumentsOverflow((uint64_t)image_width * image_height,
sizeof(*raster))) {
stride = (uint64_t)image_width * sizeof(*raster);
if (!ImgIoUtilCheckSizeArgumentsOverflow(stride, image_height)) {
fprintf(stderr, "Error! TIFF image dimension (%d x %d) is too large.\n",
image_width, image_height);
goto End;
}
// According to spec, a tile can be bigger than the image. However it should
// be a multiple of 16 and not way too large, so check that it's not more than
// twice the image size, for dimensions above some arbitrary minimum 32.
if ((TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tile_width) &&
tile_width > 32 && tile_width / 2 > image_width) ||
(TIFFGetField(tif, TIFFTAG_TILELENGTH, &tile_height) &&
tile_height > 32 && tile_height / 2 > image_height)) {
fprintf(stderr, "Error! TIFF tile dimensions are too big.\n");
goto End;
// be a multiple of 16 and not way too large, so check that it's not more
// than twice the image size, for dimensions above some arbitrary minimum
// 32. We also check that they respect WebP's dimension and memory limit.
// Note that a tile can be 6byte/px in some cases. Here we assume
// 4byte/px with sizeof(*raster), to be conservative.
if (TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tile_width) &&
TIFFGetField(tif, TIFFTAG_TILELENGTH, &tile_height)) {
if ((tile_width > 32 && tile_width / 2 > image_width) ||
(tile_height > 32 && tile_height / 2 > image_height) ||
ImgIoUtilCheckSizeArgumentsOverflow(
(uint64_t)tile_width * sizeof(*raster), tile_height)) {
fprintf(stderr, "Error! TIFF tile dimension (%d x %d) is too large.\n",
tile_width, tile_height);
goto End;
}
}
if (samples_per_px > 3 && !TIFFGetField(tif, TIFFTAG_EXTRASAMPLES,
&extra_samples, &extra_samples_ptr)) {
fprintf(stderr, "Error! Cannot retrieve TIFF ExtraSamples info.\n");
@ -215,15 +227,13 @@ int ReadTIFF(const uint8_t* const data, size_t data_size,
}
// _Tiffmalloc uses a signed type for size.
alloc_size =
(int64_t)((uint64_t)image_width * image_height * sizeof(*raster));
alloc_size = (int64_t)(stride * image_height);
if (alloc_size < 0 || alloc_size != (tsize_t)alloc_size) goto End;
raster = (uint32*)_TIFFmalloc((tsize_t)alloc_size);
if (raster != NULL) {
if (TIFFReadRGBAImageOriented(tif, image_width, image_height, raster,
ORIENTATION_TOPLEFT, 1)) {
const int stride = image_width * sizeof(*raster);
pic->width = image_width;
pic->height = image_height;
// TIFF data is ABGR
@ -241,8 +251,8 @@ int ReadTIFF(const uint8_t* const data, size_t data_size,
}
}
ok = keep_alpha
? WebPPictureImportRGBA(pic, (const uint8_t*)raster, stride)
: WebPPictureImportRGBX(pic, (const uint8_t*)raster, stride);
? WebPPictureImportRGBA(pic, (const uint8_t*)raster, (int)stride)
: WebPPictureImportRGBX(pic, (const uint8_t*)raster, (int)stride);
}
_TIFFfree(raster);
} else {