From bb93ca98d9197f6b35d062c9e10027a7afb9b38f Mon Sep 17 00:00:00 2001
From: Lian Hu <lian.hu@aiven.io>
Date: Fri, 1 Mar 2024 13:47:44 +0100
Subject: [PATCH] Check if schema already exists before create extension
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If the schema aiven_extras already exists and belongs to an
unprivileged user before adding the extension, it’s possible
to abuse it to run some queries in the context of the superuser.

[BF-2375]
---
 Makefile                             |  4 ++--
 sql/aiven_extras--1.1.11--1.1.12.sql |  1 +
 sql/aiven_extras.sql                 | 12 ++++++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 sql/aiven_extras--1.1.11--1.1.12.sql

diff --git a/Makefile b/Makefile
index 84ffa85..e4f366c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
-short_ver = 1.1.12
-last_ver = 1.1.11
+short_ver = 1.1.13
+last_ver = 1.1.12
 long_ver = $(shell git describe --long 2>/dev/null || echo $(short_ver)-0-unknown-g`git describe --always`)
 generated = aiven_extras.control \
 			sql/aiven_extras--$(short_ver).sql \
diff --git a/sql/aiven_extras--1.1.11--1.1.12.sql b/sql/aiven_extras--1.1.11--1.1.12.sql
new file mode 100644
index 0000000..e2f08fc
--- /dev/null
+++ b/sql/aiven_extras--1.1.11--1.1.12.sql
@@ -0,0 +1 @@
+-- NOOP
diff --git a/sql/aiven_extras.sql b/sql/aiven_extras.sql
index adc4294..29144d9 100644
--- a/sql/aiven_extras.sql
+++ b/sql/aiven_extras.sql
@@ -1,3 +1,15 @@
+-- Check that if schema owned by other already exist
+DO LANGUAGE plpgsql
+$$
+BEGIN
+    IF EXISTS (
+        SELECT * FROM information_schema.schemata WHERE schema_name = 'aiven_extras' AND schema_owner <> current_user
+    ) THEN
+        RAISE EXCEPTION 'Cannot create extension, schema ''aiven_extras'' owned by other user already exists';
+    END IF;
+END
+$$;
+
 DO LANGUAGE plpgsql
 $OUTER$
 DECLARE