# HG changeset patch
# User Ryan C. Gordon <icculus@icculus.org>
# Date 1518038991 18000
# Node ID fb643e371806910f1973abfdfe7f981e8dba60f5
# Parent  c5f9cbb5d2bbcb2150ba0596ea56b49efeed660d
xcf: check for some potential integer overflows.

diff -r c5f9cbb5d2bb -r fb643e371806 IMG_xcf.c
--- a/IMG_xcf.c	Wed Feb 07 16:18:54 2018 -0500
+++ b/IMG_xcf.c	Wed Feb 07 16:29:51 2018 -0500
@@ -595,6 +595,18 @@
   SDL_RWseek (src, layer->hierarchy_file_offset, RW_SEEK_SET);
   hierarchy = read_xcf_hierarchy (src);
 
+  if (hierarchy->bpp > 4) {  /* unsupported. */
+    fprintf(stderr, "Unknown Gimp image bpp (%u)\n", (unsigned int) hierarchy->bpp);
+    free_xcf_hierarchy(hierarchy);
+    return 1;
+  }
+
+  if ((hierarchy->width > 20000) || (hierarchy->height > 20000)) {  /* arbitrary limit to avoid integer overflow. */
+    fprintf(stderr, "Gimp image too large (%ux%u)\n", (unsigned int) hierarchy->width, (unsigned int) hierarchy->height);
+    free_xcf_hierarchy(hierarchy);
+    return 1;
+  }
+
   level = NULL;
   for (i = 0; hierarchy->level_file_offsets [i]; i++) {
     SDL_RWseek (src, hierarchy->level_file_offsets [i], RW_SEEK_SET);