From 5bede3305cabb9ac19babecf3ebaf64f43f7b53e Mon Sep 17 00:00:00 2001
From: Alex Rousskov <rousskov@measurement-factory.com>
Date: Sun, 12 Nov 2023 09:33:20 +0000
Subject: [PATCH] Do not update StoreEntry expiration after errorAppendEntry()
 (#1580)

errorAppendEntry() is responsible for setting entry expiration times,
which it does by calling StoreEntry::storeErrorResponse() that calls
StoreEntry::negativeCache().

This change was triggered by a vulnerability report by Joshua Rogers at
https://megamansec.github.io/Squid-Security-Audit/cache-uaf.html where
it was filed as "Use-After-Free in Cache Manager Errors". The reported
"use after free" vulnerability was unknowingly addressed by 2022 commit
1fa761a that removed excessively long "reentrant" store_client calls
responsible for the disappearance of the properly locked StoreEntry in
this (and probably other) contexts.

Conflict: context adapt
Reference: https://github.com/squid-cache/squid/commit/5bede3305cabb9ac19babecf3ebaf64f43f7b53e
---
 src/cache_manager.cc | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/cache_manager.cc b/src/cache_manager.cc
index b5a9cbecd33..08445a517a9 100644
--- a/src/cache_manager.cc
+++ b/src/cache_manager.cc
@@ -306,7 +306,6 @@ CacheManager::start(const Comm::ConnectionPointer &client, HttpRequest *request,
         const auto err = new ErrorState(ERR_INVALID_URL, Http::scNotFound, request);
         err->url = xstrdup(entry->url());
         errorAppendEntry(entry, err);
-        entry->expires = squid_curtime;
         return;
     }
 
