From: Hans Kristian Rosbach <hk-git@circlestorm.org>
Date: Fri, 24 Mar 2017 13:27:59 +0000 (+0100)
Subject: Prevent potential division-by-zero in gzfwrite and gzfread.
X-Git-Tag: 1.9.9-b1~664
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eeb195e16d075812db0f6030a66bb373bbb6e5e4;p=thirdparty%2Fzlib-ng.git

Prevent potential division-by-zero in gzfwrite and gzfread.
---

diff --git a/gzread.c b/gzread.c
index c8ec08fbd..7319365bf 100644
--- a/gzread.c
+++ b/gzread.c
@@ -378,6 +378,10 @@ size_t ZEXPORT gzfread(void *buf, size_t size, size_t nitems, gzFile file) {
     size_t len;
     gz_state *state;
 
+    /* Exit early if size is zero, also prevents potential division by zero */
+    if (size == 0)
+        return 0;
+
     /* get internal structure */
     if (file == NULL)
         return 0;
diff --git a/gzwrite.c b/gzwrite.c
index 80305261b..cfaefb145 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -248,6 +248,10 @@ size_t ZEXPORT gzfwrite(void const *buf, size_t size, size_t nitems, gzFile file
     size_t len;
     gz_state *state;
 
+    /* Exit early if size is zero, also prevents potential division by zero */
+    if (size == 0)
+        return 0;
+
     /* get internal structure */
     if (file == NULL)
         return 0;