libpng: Reject oversized iCCP profile length

third_party/libpng/png.c

Index: third_party/libpng/png.c
diff --git a/third_party/libpng/png.c b/third_party/libpng/png.c
index 65299a0fa6a61b3fa30734832172bbc1a909b6a0..6e4cbedcb90c9641cc75e8a1d4f1bc51da8ecdf1 100644
--- a/third_party/libpng/png.c
+++ b/third_party/libpng/png.c
@@ -1931,8 +1931,8 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
 static const png_byte D50_nCIEXYZ[12] =
    { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d };
 
-int /* PRIVATE */
-png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+static int /* bool */
+icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
    png_const_charp name, png_uint_32 profile_length)
 {
    if (profile_length < 132)
@@ -1942,6 +1942,40 @@ png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
    return 1;
 }
 
+#ifdef PNG_READ_iCCP_SUPPORTED
+int /* PRIVATE */
+png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_uint_32 profile_length)
+{
+   if (!icc_check_length(png_ptr, colorspace, name, profile_length))
+      return 0;
+
+   /* This needs to be here because the 'normal' check is in
+    * png_decompress_chunk, yet this happens after the attempt to
+    * png_malloc_base the required data.  We only need this on read; on write
+    * the caller supplies the profile buffer so libpng doesn't allocate it.  See
+    * the call to icc_check_length below (the write case).
+    */
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
+      else if (png_ptr->user_chunk_malloc_max > 0 &&
+               png_ptr->user_chunk_malloc_max < profile_length)
+         return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+             "exceeds application limits");
+#  elif PNG_USER_CHUNK_MALLOC_MAX > 0
+      else if (PNG_USER_CHUNK_MALLOC_MAX < profile_length)
+         return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+             "exceeds libpng limits");
+#  else /* !SET_USER_LIMITS */
+      /* This will get compiled out on all 32-bit and better systems. */
+      else if (PNG_SIZE_MAX < profile_length)
+         return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+             "exceeds system limits");
+#  endif /* !SET_USER_LIMITS */
+
+   return 1;
+}
+#endif /* READ_iCCP */
+
 int /* PRIVATE */
 png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
    png_const_charp name, png_uint_32 profile_length,
@@ -2379,7 +2413,7 @@ png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
    if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
       return 0;
 
-   if (png_icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
+   if (icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
        png_icc_check_header(png_ptr, colorspace, name, profile_length, profile,
           color_type) != 0 &&
        png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,