From 4087a2a2d7d3fa970f0dd3e5f2a82d5a94b84aef Mon Sep 17 00:00:00 2001
From: d0k3 <tore.anon@gmail.com>
Date: Wed, 7 Mar 2018 01:22:15 +0100
Subject: [PATCH] Stricter checking for ExeFS files

fixes #321
---
 arm9/source/game/exefs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arm9/source/game/exefs.c b/arm9/source/game/exefs.c
index 433bd67..06ca939 100644
--- a/arm9/source/game/exefs.c
+++ b/arm9/source/game/exefs.c
@@ -9,9 +9,11 @@ u32 ValidateExeFsHeader(ExeFsHeader* exefs, u32 size) {
         ExeFsFileHeader* file = exefs->files + i;
         u8* hash = exefs->hashes[9 - i];
         if (file->size == 0) continue;
+        if (!*(file->name)) return 1; // zero filename -> not a valid ExeFS
         if (file->offset % NCCH_MEDIA_UNIT) return 1; // not aligned to media unit, failed
         if (file->offset < data_size) return 1; // overlapping data, failed
         if (memcmp(hash, zeroes, 32) == 0) return 1; // hash not set, failed
+        if (file->size >= 0xFFFFFE00) return 1; // obviously an improper value, failed
         data_size = file->offset + align(file->size, NCCH_MEDIA_UNIT);
         n_files++;
     }