From 1e89ec5759ab03b9f6bed063968e5de195a72524 Mon Sep 17 00:00:00 2001
From: PobreGato <315121269+pobregat0@users.noreply.github.com>
Date: Mon, 12 Oct 2026 21:28:29 -0400
Subject: [PATCH] fix overflow in tunnel build bandwidth options check

---
 libi2pd/TransitTunnel.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libi2pd/TransitTunnel.cpp b/libi2pd/TransitTunnel.cpp
index 589681bc..f6aaf08f 100644
--- a/libi2pd/TransitTunnel.cpp
+++ b/libi2pd/TransitTunnel.cpp
@@ -375,7 +375,7 @@ namespace tunnel
 					{
 						bwLimit = i2p::context.GetBandwidthLimit ()*1024; // in bytes
 						bwUse = i2p::transport::transports.GetTransitBandwidth ();
-						if (bw*1024 + bwUse > bwLimit)
+						if ((uint64_t)bw*1024 + bwUse > bwLimit) // bw comes from the request, 32-bit product overflows
 							retCode = 30;
 					}
 					if (!retCode && buildOptions.Get (TRANSIT_TUNNEL_REQUESTED_BANDWIDTH, bw))
@@ -387,7 +387,7 @@ namespace tunnel
 						if (bwUse < bwLimit)
 						{
 							availableBandwidth = bwLimit - bwUse;
-							if (bw*1024 > availableBandwidth)
+							if ((uint64_t)bw*1024 > availableBandwidth)
 								availableBandwidth /= 1024;
 							else
 								availableBandwidth = bw; // reply with requested bandwidth