From 5304ae14655a67b9a3db00563fe44d9abd6de4f0 Mon Sep 17 00:00:00 2001
From: Dirk Lemstra <dirk@git.imagemagick.org>
Date: Sat, 12 Aug 2017 10:44:24 +0200
Subject: [PATCH] Fixed buffer overflow reported in #670

---
 coders/sfw.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/coders/sfw.c b/coders/sfw.c
index 5d2cc60c2..4a778ea22 100644
--- a/coders/sfw.c
+++ b/coders/sfw.c
@@ -126,16 +126,15 @@ static unsigned char *SFWScan(const unsigned char *p,const unsigned char *q,
   register ssize_t
     i;
 
-  if ((p+length) < q)
-    while (p < q)
-    {
-      for (i=0; i < (ssize_t) length; i++)
-        if (p[i] != target[i])
-          break;
-      if (i == (ssize_t) length)
-        return((unsigned char *) p);
-      p++;
-    }
+  while ((p+length) < q)
+  {
+    for (i=0; i < (ssize_t) length; i++)
+      if (p[i] != target[i])
+        break;
+    if (i == (ssize_t) length)
+      return((unsigned char *) p);
+    p++;
+  }
   return((unsigned char *) NULL);
 }
 
-- 
2.40.0