From dbec5ff0bcd65709f65e1d651853fedc39fb00a1 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Fri, 28 Mar 2014 09:15:09 -0700
Subject: [PATCH] Fix out-of-bounds read when looking for subtitles in a
 matroska file with no subtitles

---
 src/mkv_wrap.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/mkv_wrap.cpp b/src/mkv_wrap.cpp
index 05b1051a6..835762f1e 100644
--- a/src/mkv_wrap.cpp
+++ b/src/mkv_wrap.cpp
@@ -67,6 +67,10 @@ struct MkvStdIO final : InputStream {
 		if (pos == self->file.size())
 			return 0;
 
+		auto remaining = self->file.size() - pos;
+		if (remaining < INT_MAX)
+			count = std::min(static_cast<int>(remaining), count);
+
 		try {
 			memcpy(buffer, self->file.read(pos, count), count);
 		}