From 9141f1df0d6ecb84f298633ba03569bbf5c842d0 Mon Sep 17 00:00:00 2001
From: Hugo Lefeuvre <hle@debian.org>
Date: Wed, 17 Jan 2018 10:52:47 +0100
Subject: [PATCH 26/29] Fix left shift of a negative value in readSBits.

Check for !number before left-shifting by (number-1).

This commit fixes CVE-2018-5294 (fixes #97).
---
 util/read.c | 2 +-
 1 file changed, 1 insertions(+), 1 deletion(-)

diff --git a/util/read.c b/util/read.c
index 32f4c673..bce95ef1 100644
--- a/util/read.c
+++ b/util/read.c
@@ -107,7 +107,7 @@ int readSBits(FILE *f, int number)
 {
   int num = readBits(f, number);
 
-  if(num & (1<<(number-1)))
+  if(number && num & (1<<(number-1)))
     return num - (1<<number);
   else
     return num;
-- 
2.14.3