From ab5af9fadcc90cdaa086986806bfb7eac3a80404 Mon Sep 17 00:00:00 2001
From: Andrew Ashikhmin <34320705+yperbasis@users.noreply.github.com>
Date: Thu, 24 Oct 2024 13:12:59 +0200
Subject: [PATCH] headerdownload: fix OOM due to inifinitely growing children
 in link (#12454)

Cherry pick #12405 into `release/2.61`

Co-authored-by: milen <94537774+taratorio@users.noreply.github.com>
---
 turbo/stages/headerdownload/header_algos.go | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/turbo/stages/headerdownload/header_algos.go b/turbo/stages/headerdownload/header_algos.go
index 4604ee360bc..7d177607efe 100644
--- a/turbo/stages/headerdownload/header_algos.go
+++ b/turbo/stages/headerdownload/header_algos.go
@@ -160,6 +160,11 @@ func (hd *HeaderDownload) removeUpwards(link *Link) {
 	if link == nil {
 		return
 	}
+	if link.header != nil {
+		if parentLink, ok := hd.links[link.header.ParentHash]; ok {
+			parentLink.RemoveChild(link)
+		}
+	}
 	var toRemove = []*Link{link}
 	for len(toRemove) > 0 {
 		removal := toRemove[len(toRemove)-1]
@@ -514,8 +519,6 @@ func (hd *HeaderDownload) InsertHeader(hf FeedHeaderFunc, terminalTotalDifficult
 		}
 		if bad {
 			// If the link or its parent is marked bad, throw it out
-			hd.moveLinkToQueue(link, NoQueue)
-			delete(hd.links, link.hash)
 			hd.removeUpwards(link)
 			dataflow.HeaderDownloadStates.AddChange(link.blockHeight, dataflow.HeaderBad)
 			hd.stats.RejectedBadHeaders++
@@ -532,12 +535,7 @@ func (hd *HeaderDownload) InsertHeader(hf FeedHeaderFunc, terminalTotalDifficult
 					return false, false, 0, lastTime, nil // prevent removal of the link from the hd.linkQueue
 				} else {
 					hd.logger.Debug("[downloader] Verification failed for header", "hash", link.hash, "height", link.blockHeight, "err", err)
-					hd.moveLinkToQueue(link, NoQueue)
-					delete(hd.links, link.hash)
 					hd.removeUpwards(link)
-					if parentLink, ok := hd.links[link.header.ParentHash]; ok {
-						parentLink.RemoveChild(link)
-					}
 					dataflow.HeaderDownloadStates.AddChange(link.blockHeight, dataflow.HeaderEvicted)
 					hd.stats.InvalidHeaders++
 					return true, false, 0, lastTime, nil