From 41118e17f87561afc8cbe1f3dd528624f06906a7 Mon Sep 17 00:00:00 2001
From: Roman Zeyde <me@romanzey.de>
Date: Sun, 14 Dec 2025 10:17:07 +0100
Subject: [PATCH] blockstorage: simplify partial block read validation

Use `SaturatingAdd` following https://github.com/bitcoin/bitcoin/pull/33657#discussion_r2610832092.
---
 src/node/blockstorage.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 22c8f619e60..e39b4163fc5 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -1083,7 +1083,7 @@ BlockManager::ReadRawBlockResult BlockManager::ReadRawBlock(const FlatFilePos& p
 
         if (block_part) {
             const auto [offset, size]{*block_part};
-            if (size == 0 || offset >= blk_size || size > blk_size - offset) {
+            if (size == 0 || SaturatingAdd(offset, size) > blk_size) {
                 return util::Unexpected{ReadRawError::BadPartRange}; // Avoid logging - offset/size come from untrusted REST input
             }
             filein.seek(offset, SEEK_CUR);