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[libpng16] Prevent reading over-length PLTE chunk (Cosmin Truta).

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Glenn Randers-Pehrson
2015-10-30 07:57:49 -05:00
parent 06509be841
commit a901eb3ce6
7 changed files with 34 additions and 28 deletions
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13
pngset.c
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@@ -1,7 +1,7 @@
/* pngset.c - storage of image information into info struct
*
* Last changed in libpng 1.6.18 [July 23, 2015]
* Last changed in libpng 1.6.19 [(PENDING RELEASE)]
* Copyright (c) 1998-2015 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -513,12 +513,17 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
png_const_colorp palette, int num_palette)
{
png_uint_32 max_palette_length;
png_debug1(1, "in %s storage function", "PLTE");
if (png_ptr == NULL || info_ptr == NULL)
return;
if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH)
max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
(1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
if (num_palette < 0 || num_palette > max_palette_length)
{
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
png_error(png_ptr, "Invalid palette length");
@@ -551,8 +556,8 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
/* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
* of num_palette entries, in case of an invalid PNG file that has
* too-large sample values.
* of num_palette entries, in case of an invalid PNG file or incorrect
* call to png_set_PLTE() with too-large sample values.
*/
png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));