From 2182bc963d2e0fc12a94adfdf92c7b31d593074e Mon Sep 17 00:00:00 2001
From: KIU Shueng Chuan <nixchuan@gmail.com>
Date: Sat, 25 Jul 2015 17:46:46 +0800
Subject: [PATCH] check for potential unsigned integer wraparound before adding

---
 src/msg.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/msg.cpp b/src/msg.cpp
index 07ce88e4..d8519f32 100644
--- a/src/msg.cpp
+++ b/src/msg.cpp
@@ -103,8 +103,9 @@ int zmq::msg_t::init_size (size_t size_)
         u.lmsg.type = type_lmsg;
         u.lmsg.flags = 0;
         u.lmsg.routing_id = 0;
-        u.lmsg.content =
-            (content_t*) malloc (sizeof (content_t) + size_);
+        u.lmsg.content = NULL;
+        if (sizeof (content_t) + size_ > size_)
+            u.lmsg.content = (content_t*) malloc (sizeof (content_t) + size_);
         if (unlikely (!u.lmsg.content)) {
             errno = ENOMEM;
             return -1;