Re: glibc qsort() vulnerability

Hi! 
I think there's a bug here: 

diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c 
index 37998f7387..2ab344c1f8 100644 
--- a/src/backend/postmaster/autovacuum.c 
+++ b/src/backend/postmaster/autovacuum.c 
@@ -78,6 +78,7 @@ 
 #include "catalog/pg_database.h" 
 #include "commands/dbcommands.h" 
 #include "commands/vacuum.h" 
+#include "common/int.h" 
 #include "lib/ilist.h" 
 #include "libpq/pqsignal.h" 
 #include "miscadmin.h" 
@@ -1120,10 +1121,8 @@ rebuild_database_list(Oid newdb) 
 static int 
 db_comparator(const void *a, const void *b) 
 { 
-    if (((const avl_dbase *) a)->adl_score == ((const avl_dbase *) b)->adl_score) 
-        return 0; 
-    else 
-        return (((const avl_dbase *) a)->adl_score < ((const avl_dbase *) b)->adl_score) ? 1 : -1; 
+    return pg_cmp_s32(((const avl_dbase *) a)->adl_score, 
+                      ((const avl_dbase *) b)->adl_score); 
 } 

It breaks the database vacuuming order. The order should clearly be different here. 
This bug was introduced in PostgreSQL 17. I have attached а fix. 

Best regards, 
Rustam Khamidullin, Postgres Professional