Fix undefined behavior caused by referencing the returned buffer by std::string::c_str() when the object is temporary

Thanks to @ChrisTX for pointing this out
Fixes #257 reported by @helloall

4 files changed, 10 insertions, 5 deletions

diff --git a/src/modules/m_alias.cpp b/src/modules/m_alias.cpp
index ec426fe9b..6cb336c83 100644
--- a/src/modules/m_alias.cpp
+++ b/src/modules/m_alias.cpp
@@ -87,7 +87,8 @@ class ModuleAlias : public Module
 		{
 			ConfigTag* tag = i->second;
 			Alias a;
-			a.AliasedCommand = tag->getString("text").c_str();
+			std::string aliastext = tag->getString("text");
+			a.AliasedCommand = aliastext.c_str();
 			tag->readString("replace", a.ReplaceFormat, true);
 			a.RequiredNick = tag->getString("requires");
 			a.ULineOnly = tag->getBool("uline");
diff --git a/src/modules/m_httpd.cpp b/src/modules/m_httpd.cpp
index 0584e97c5..bf86c9091 100644
--- a/src/modules/m_httpd.cpp
+++ b/src/modules/m_httpd.cpp
@@ -282,7 +282,7 @@ class HttpServerSocket : public BufferedSocket
 			return;
 		}
 
-		if (headers.IsSet("Content-Length") && (postsize = atoi(headers.GetHeader("Content-Length").c_str())) != 0)
+		if (headers.IsSet("Content-Length") && (postsize = ConvToInt(headers.GetHeader("Content-Length"))) != 0)
 		{
 			InternalState = HTTP_SERVE_RECV_POSTDATA;
 
diff --git a/src/modules/m_operlevels.cpp b/src/modules/m_operlevels.cpp
index 7e28f6c21..4fc4c6aef 100644
--- a/src/modules/m_operlevels.cpp
+++ b/src/modules/m_operlevels.cpp
@@ -42,8 +42,11 @@ class ModuleOperLevels : public Module
 			// oper killing an oper?
 			if (IS_OPER(dest) && IS_OPER(source))
 			{
-				long dest_level = atol(dest->oper->getConfig("level").c_str());
-				long source_level = atol(source->oper->getConfig("level").c_str());
+				std::string level = dest->oper->getConfig("level");
+				long dest_level = atol(level.c_str());
+				level = source->oper->getConfig("level");
+				long source_level = atol(level.c_str());
+
 				if (dest_level > source_level)
 				{
 					if (IS_LOCAL(source)) ServerInstance->SNO->WriteGlobalSno('a', "Oper %s (level %ld) attempted to /kill a higher oper: %s (level %ld): Reason: %s",source->nick.c_str(),source_level,dest->nick.c_str(),dest_level,reason.c_str());
diff --git a/src/modules/m_spanningtree/utils.cpp b/src/modules/m_spanningtree/utils.cpp
index 75d4eaca3..11fdeb6cc 100644
--- a/src/modules/m_spanningtree/utils.cpp
+++ b/src/modules/m_spanningtree/utils.cpp
@@ -374,7 +374,8 @@ void SpanningTreeUtilities::ReadConfiguration()
 	{
 		ConfigTag* tag = i->second;
 		reference<Link> L = new Link(tag);
-		L->Name = tag->getString("name").c_str();
+		std::string linkname = tag->getString("name");
+		L->Name = linkname.c_str();
 		L->AllowMask = tag->getString("allowmask");
 		L->IPAddr = tag->getString("ipaddr");
 		L->Port = tag->getInt("port");