From b2478a9ba9ed76d7c858419e3f677cc454591d45 Mon Sep 17 00:00:00 2001
From: Christopher Kohlhoff <chris@kohlhoff.com>
Date: Mon, 1 Dec 2025 22:47:38 +1100
Subject: [PATCH] Remove _FORTIFY_SOURCE workaround. Check size when processing
 addrinfo.

The previous workaround for _FORTIFY_SOURCE warnings increased the size
of all IP endpoint objects. Instead, try fixing the warning at the point
where it occurs, by limiting the length memcpy-ed while processing the
addrinfo results from getaddrinfo.
---
 .../boost/asio/ip/basic_resolver_results.hpp  | 22 ++++++++++++-------
 include/boost/asio/ip/detail/endpoint.hpp     | 12 ++++------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/include/boost/asio/ip/basic_resolver_results.hpp b/include/boost/asio/ip/basic_resolver_results.hpp
index ea97b324..e1ebcbc1 100644
--- a/include/boost/asio/ip/basic_resolver_results.hpp
+++ b/include/boost/asio/ip/basic_resolver_results.hpp
@@ -133,14 +133,20 @@ public:
       if (address_info->ai_family == BOOST_ASIO_OS_DEF(AF_INET)
           || address_info->ai_family == BOOST_ASIO_OS_DEF(AF_INET6))
       {
-        using namespace std; // For memcpy.
-        typename InternetProtocol::endpoint endpoint;
-        endpoint.resize(static_cast<std::size_t>(address_info->ai_addrlen));
-        memcpy(endpoint.data(), address_info->ai_addr,
-            address_info->ai_addrlen);
-        results.values_->push_back(
-            basic_resolver_entry<InternetProtocol>(endpoint,
-              actual_host_name, service_name));
+        const std::size_t expected_size =
+          address_info->ai_family == BOOST_ASIO_OS_DEF(AF_INET)
+            ? sizeof(boost::asio::detail::sockaddr_in4_type)
+            : sizeof(boost::asio::detail::sockaddr_in6_type);
+        if (address_info->ai_addrlen >= expected_size)
+        {
+          using namespace std; // For memcpy.
+          typename InternetProtocol::endpoint endpoint;
+          endpoint.resize(expected_size);
+          memcpy(endpoint.data(), address_info->ai_addr, expected_size);
+          results.values_->push_back(
+              basic_resolver_entry<InternetProtocol>(endpoint,
+                actual_host_name, service_name));
+        }
       }
       address_info = address_info->ai_next;
     }
diff --git a/include/boost/asio/ip/detail/endpoint.hpp b/include/boost/asio/ip/detail/endpoint.hpp
index 8483474b..dc84fd2e 100644
--- a/include/boost/asio/ip/detail/endpoint.hpp
+++ b/include/boost/asio/ip/detail/endpoint.hpp
@@ -60,13 +60,13 @@ public:
   // Get the underlying endpoint in the native type.
   boost::asio::detail::socket_addr_type* data() noexcept
   {
-    return &data_.base[0];
+    return &data_.base;
   }
 
   // Get the underlying endpoint in the native type.
   const boost::asio::detail::socket_addr_type* data() const noexcept
   {
-    return &data_.base[0];
+    return &data_.base;
   }
 
   // Get the underlying size of the endpoint in the native type.
@@ -111,7 +111,7 @@ public:
   // Determine whether the endpoint is IPv4.
   bool is_v4() const noexcept
   {
-    return data_.base[0].sa_family == BOOST_ASIO_OS_DEF(AF_INET);
+    return data_.base.sa_family == BOOST_ASIO_OS_DEF(AF_INET);
   }
 
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -123,11 +123,7 @@ private:
   // The underlying IP socket address.
   union data_union
   {
-#if defined(_FORTIFY_SOURCE)
-    boost::asio::detail::socket_addr_type base[8];
-#else // defined(_FORTIFY_SOURCE)
-    boost::asio::detail::socket_addr_type base[1];
-#endif // defined(_FORTIFY_SOURCE)
+    boost::asio::detail::socket_addr_type base;
     boost::asio::detail::sockaddr_in4_type v4;
     boost::asio::detail::sockaddr_in6_type v6;
   } data_;