From e88052e34c4efd7a8b79effcde9d51cd4e5dd6ca Mon Sep 17 00:00:00 2001
From: Serris Santos <serrisnlew@gmail.com>
Date: Tue, 17 Mar 2026 14:17:57 -0700
Subject: [PATCH 1/3] Check valid parent selection hash string

---
 src/proxy/ParentSelection.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/proxy/ParentSelection.cc b/src/proxy/ParentSelection.cc
index b282fba7b38..47bb01b1bbd 100644
--- a/src/proxy/ParentSelection.cc
+++ b/src/proxy/ParentSelection.cc
@@ -556,6 +556,11 @@ ParentRecord::ProcessParents(char *val, bool isPrimary)
       errPtr = "Parent string is empty";
       goto MERROR;
     }
+    if (tmp3 && strlen(tmp3) > MAXDNAME) {
+      errPtr = "Parent hash_string is too long";
+      goto MERROR;
+    }
+
     // Update the pRecords
     if (isPrimary) {
       memcpy(this->parents[i].hostname, current, tmp - current);

From 1ddcca1774fc9a3bb52775f8f6b9926c183aa22b Mon Sep 17 00:00:00 2001
From: Serris Santos <serrisnlew@gmail.com>
Date: Tue, 24 Mar 2026 12:52:48 -0700
Subject: [PATCH 2/3] add regression test

---
 src/proxy/ParentSelection.cc | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/proxy/ParentSelection.cc b/src/proxy/ParentSelection.cc
index 47bb01b1bbd..c312588d691 100644
--- a/src/proxy/ParentSelection.cc
+++ b/src/proxy/ParentSelection.cc
@@ -32,6 +32,7 @@
 #include "tscore/Regression.h"
 #include "tscore/Tokenizer.h"
 
+#include <string>
 #include <string_view>
 
 using namespace std::literals;
@@ -557,7 +558,7 @@ ParentRecord::ProcessParents(char *val, bool isPrimary)
       goto MERROR;
     }
     if (tmp3 && strlen(tmp3) > MAXDNAME) {
-      errPtr = "Parent hash_string is too long";
+      errPtr = "Parent hash string is too long";
       goto MERROR;
     }
 
@@ -1953,6 +1954,37 @@ EXCLUSIVE_REGRESSION_TEST(PARENTSELECTION)(RegressionTest * /* t ATS_UNUSED */,
   FP;
   RE(verify(result, ParentResultType::SPECIFIED, "minnie", 80), 213);
 
+  // Test 214
+  // Overlong hash_string (MAXDNAME chars) should be rejected by ProcessParents.
+  // The entry is discarded so findParent returns DIRECT.
+  {
+    tbl[0] = '\0';
+    ST(214);
+    std::string long_hash(MAXDNAME, 'a');
+    std::string cfg = "dest_domain=. parent=host:80&" + long_hash + " round_robin=consistent_hash go_direct=true\n";
+    ink_strlcpy(tbl, cfg.c_str(), sizeof(tbl));
+    REBUILD;
+    REINIT;
+    br(request, "overlong.hash.net");
+    FP;
+    RE(verify(result, ParentResultType::DIRECT, nullptr, 0), 214);
+  }
+
+  // Test 215
+  // Max-length hash_string that fits (MAXDNAME-1 chars) should be accepted.
+  {
+    tbl[0] = '\0';
+    ST(215);
+    std::string max_hash(MAXDNAME - 1, 'b');
+    std::string cfg = "dest_domain=. parent=host:80&" + max_hash + " round_robin=consistent_hash go_direct=false\n";
+    ink_strlcpy(tbl, cfg.c_str(), sizeof(tbl));
+    REBUILD;
+    REINIT;
+    br(request, "maxlen.hash.net");
+    FP;
+    RE(verify(result, ParentResultType::SPECIFIED, "host", 80), 215);
+  }
+
   delete request;
   delete result;
   delete params;

From 287ba18b1024cd7dd2dbb91a521de5e1d0cc950d Mon Sep 17 00:00:00 2001
From: Serris Santos <serrisnlew@gmail.com>
Date: Wed, 25 Mar 2026 10:28:27 -0700
Subject: [PATCH 3/3] off by one

---
 src/proxy/ParentSelection.cc | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/proxy/ParentSelection.cc b/src/proxy/ParentSelection.cc
index c312588d691..a1bc20452fb 100644
--- a/src/proxy/ParentSelection.cc
+++ b/src/proxy/ParentSelection.cc
@@ -557,7 +557,7 @@ ParentRecord::ProcessParents(char *val, bool isPrimary)
       errPtr = "Parent string is empty";
       goto MERROR;
     }
-    if (tmp3 && strlen(tmp3) > MAXDNAME) {
+    if (tmp3 && strlen(tmp3 + 1) > MAXDNAME) {
       errPtr = "Parent hash string is too long";
       goto MERROR;
     }
@@ -1955,12 +1955,12 @@ EXCLUSIVE_REGRESSION_TEST(PARENTSELECTION)(RegressionTest * /* t ATS_UNUSED */,
   RE(verify(result, ParentResultType::SPECIFIED, "minnie", 80), 213);
 
   // Test 214
-  // Overlong hash_string (MAXDNAME chars) should be rejected by ProcessParents.
+  // Overlong hash_string (exceeding MAXDNAME chars) should be rejected by ProcessParents.
   // The entry is discarded so findParent returns DIRECT.
   {
     tbl[0] = '\0';
     ST(214);
-    std::string long_hash(MAXDNAME, 'a');
+    std::string long_hash(MAXDNAME + 1, 'a');
     std::string cfg = "dest_domain=. parent=host:80&" + long_hash + " round_robin=consistent_hash go_direct=true\n";
     ink_strlcpy(tbl, cfg.c_str(), sizeof(tbl));
     REBUILD;
@@ -1971,11 +1971,11 @@ EXCLUSIVE_REGRESSION_TEST(PARENTSELECTION)(RegressionTest * /* t ATS_UNUSED */,
   }
 
   // Test 215
-  // Max-length hash_string that fits (MAXDNAME-1 chars) should be accepted.
+  // Max-length hash_string that fits (MAXDNAME chars) should be accepted.
   {
     tbl[0] = '\0';
     ST(215);
-    std::string max_hash(MAXDNAME - 1, 'b');
+    std::string max_hash(MAXDNAME, 'b');
     std::string cfg = "dest_domain=. parent=host:80&" + max_hash + " round_robin=consistent_hash go_direct=false\n";
     ink_strlcpy(tbl, cfg.c_str(), sizeof(tbl));
     REBUILD;