From 71c62ea7cb95ce987a7bca41181bf963ecf12d39 Mon Sep 17 00:00:00 2001
From: Sadie Powell
Date: Sat, 25 Dec 2021 10:58:49 +0000
Subject: Make packing PTR queries a bit more robust.

There is no first party modules which could be compromised before
this check was added but its better to be safe wherever possible.
---
 src/coremods/core_dns.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/coremods/core_dns.cpp b/src/coremods/core_dns.cpp
index 8ebc1b57d..f3febc36b 100644
--- a/src/coremods/core_dns.cpp
+++ b/src/coremods/core_dns.cpp
@@ -279,7 +279,7 @@ class Packet : public Query
 	unsigned short Pack(unsigned char* output, unsigned short output_size)
 	{
 		if (output_size < HEADER_LENGTH)
-			throw Exception("Unable to pack packet");
+			throw Exception("Unable to pack oversized packet header");
 
 		unsigned short pos = 0;
 
@@ -302,7 +302,8 @@ class Packet : public Query
 			if (q.type == QUERY_PTR)
 			{
 				irc::sockets::sockaddrs ip;
-				irc::sockets::aptosa(q.name, 0, ip);
+				if (!irc::sockets::aptosa(q.name, 0, ip))
+					throw Exception("Unable to pack packet with malformed IP for PTR lookup");
 
 				if (q.name.find(':') != std::string::npos)
 				{
@@ -333,7 +334,7 @@ class Packet : public Query
 			this->PackName(output, output_size, pos, q.name);
 
 			if (pos + 4 >= output_size)
-				throw Exception("Unable to pack packet");
+				throw Exception("Unable to pack oversized packet body");
 
 			short s = htons(q.type);
 			memcpy(&output[pos], &s, 2);
-- 
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