[sfnt] Fix heap buffer overflow.

This is CVE-2020-15999.

* src/sfnt/pngshim.c (Load_SBit_Png): Test bitmap size earlier.
This commit is contained in:
Werner Lemberg 2020-11-19 19:18:32 +00:00 committed by roytam1
commit 94187c71cf

View file

@ -327,6 +327,13 @@
if ( populate_map_and_metrics )
{
/* reject too large bitmaps similarly to the rasterizer */
if ( map->rows > 0x7FFF || map->width > 0x7FFF )
{
error = FT_THROW( Array_Too_Large );
goto DestroyExit;
}
metrics->width = (FT_UShort)imgWidth;
metrics->height = (FT_UShort)imgHeight;
@ -335,13 +342,6 @@
map->pixel_mode = FT_PIXEL_MODE_BGRA;
map->pitch = (int)( map->width * 4 );
map->num_grays = 256;
/* reject too large bitmaps similarly to the rasterizer */
if ( map->rows > 0x7FFF || map->width > 0x7FFF )
{
error = FT_THROW( Array_Too_Large );
goto DestroyExit;
}
}
/* convert palette/gray image to rgb */