Bug#797165: CVE-2015-0852: integer overflow in PluginPCX.cpp
tags 797165 +patch
thanks
Could someone please check attached patch? Thanks.
Description: fix integer overflow
Origin: upstream
http://freeimage.cvs.sourceforge.net/viewvc/freeimage/FreeImage/Source/FreeImage/PluginPCX.cpp?view=patch&r1=1.17&r2=1.18&pathrev=MAIN
http://freeimage.cvs.sourceforge.net/viewvc/freeimage/FreeImage/Source/FreeImage/PluginPCX.cpp?view=patch&r1=1.18&r2=1.19&pathrev=MAIN
Bug-Debian: https://bugs.debian.org/797165
Last-Update: 2015-09-14
---
This patch header follows DEP-3: http://dep.debian.net/deps/dep3/
--- a/Source/FreeImage/PluginPCX.cpp
+++ b/Source/FreeImage/PluginPCX.cpp
@@ -347,12 +347,14 @@
try {
// check PCX identifier
-
- long start_pos = io->tell_proc(handle);
- BOOL validated = pcx_validate(io, handle);
- io->seek_proc(handle, start_pos, SEEK_SET);
- if(!validated) {
- throw FI_MSG_ERROR_MAGIC_NUMBER;
+ // (note: should have been already validated using FreeImage_GetFileType but check again)
+ {
+ long start_pos = io->tell_proc(handle);
+ BOOL validated = pcx_validate(io, handle);
+ io->seek_proc(handle, start_pos, SEEK_SET);
+ if(!validated) {
+ throw FI_MSG_ERROR_MAGIC_NUMBER;
+ }
}
// process the header
@@ -366,20 +368,38 @@
SwapHeader(&header);
#endif
- // allocate a new DIB
+ // process the window
+ const WORD *window = header.window; // left, upper, right,lower pixel coord.
+ const int left = window[0];
+ const int top = window[1];
+ const int right = window[2];
+ const int bottom = window[3];
- unsigned width = header.window[2] - header.window[0] + 1;
- unsigned height = header.window[3] - header.window[1] + 1;
- unsigned bitcount = header.bpp * header.planes;
-
- if (bitcount == 24) {
- dib = FreeImage_AllocateHeader(header_only, width, height, bitcount, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
- } else {
- dib = FreeImage_AllocateHeader(header_only, width, height, bitcount);
+ // check image size
+ if((left >= right) || (top >= bottom)) {
+ throw FI_MSG_ERROR_PARSING;
}
- // if the dib couldn't be allocated, throw an error
+ const unsigned width = right - left + 1;
+ const unsigned height = bottom - top + 1;
+ const unsigned bitcount = header.bpp * header.planes;
+
+ // allocate a new DIB
+ switch(bitcount) {
+ case 1:
+ case 4:
+ case 8:
+ dib = FreeImage_AllocateHeader(header_only, width, height, bitcount);
+ break;
+ case 24:
+ dib = FreeImage_AllocateHeader(header_only, width, height, bitcount, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
+ break;
+ default:
+ throw FI_MSG_ERROR_DIB_MEMORY;
+ break;
+ }
+ // if the dib couldn't be allocated, throw an error
if (!dib) {
throw FI_MSG_ERROR_DIB_MEMORY;
}
@@ -426,19 +446,23 @@
if (palette_id == 0x0C) {
BYTE *cmap = (BYTE*)malloc(768 * sizeof(BYTE));
- io->read_proc(cmap, 768, 1, handle);
- pal = FreeImage_GetPalette(dib);
- BYTE *pColormap = &cmap[0];
+ if(cmap) {
+ io->read_proc(cmap, 768, 1, handle);
- for(int i = 0; i < 256; i++) {
- pal[i].rgbRed = pColormap[0];
- pal[i].rgbGreen = pColormap[1];
- pal[i].rgbBlue = pColormap[2];
- pColormap += 3;
+ pal = FreeImage_GetPalette(dib);
+ BYTE *pColormap = &cmap[0];
+
+ for(int i = 0; i < 256; i++) {
+ pal[i].rgbRed = pColormap[0];
+ pal[i].rgbGreen = pColormap[1];
+ pal[i].rgbBlue = pColormap[2];
+ pColormap += 3;
+ }
+
+ free(cmap);
}
- free(cmap);
}
// wrong palette ID, perhaps a gray scale is needed ?
@@ -466,9 +490,9 @@
// calculate the line length for the PCX and the DIB
// length of raster line in bytes
- unsigned linelength = header.bytes_per_line * header.planes;
+ const unsigned linelength = header.bytes_per_line * header.planes;
// length of DIB line (rounded to DWORD) in bytes
- unsigned pitch = FreeImage_GetPitch(dib);
+ const unsigned pitch = FreeImage_GetPitch(dib);
// run-length encoding ?
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