From b5091279568339213978adc42d98b1053c17b23d Mon Sep 17 00:00:00 2001
From: Mahendra Singh Thalor <mahi6run@gmail.com>
Date: Mon, 2 Feb 2026 10:52:29 +0530
Subject: [PATCH 1/2] don't allow newline or carriage return character in name 
 for  database/user/role

While creating database, if database name has any newline or carriage
return character in name, then through error becuase these special
character are not allowed in dbname when dump command is executed.

do same for "CREATE ROLE", "CREATE USER" also.

This will add check for:
"CREATE DATABASE", "CREATE ROLE", "CREATE USER",
"RENAME DATABASE/USER/ROLE"

-------------------------
As we will not allow these \n\r in names, then we will never get these
names in dump also.

If we are dumping from older branch, then we will fail with same old error.
(dump will fail in older branches so no need to add extra handling for dump.)

Also remove comment added by 142c24c23447f212e642a0ffac9af878b93f490d commit.

Remove one test of 8b845520fb0aa50fea7aae44a45cee1b6d87845d commit.
---
 src/backend/commands/dbcommands.c               |  4 ++++
 src/backend/commands/define.c                   | 17 +++++++++++++++++
 src/backend/commands/user.c                     |  4 ++++
 src/bin/pg_dump/t/010_dump_connstr.pl           | 14 --------------
 src/bin/scripts/t/020_createdb.pl               | 12 ++++++++++++
 src/fe_utils/string_utils.c                     |  6 ------
 src/include/commands/defrem.h                   |  1 +
 .../modules/unsafe_tests/expected/rolenames.out |  4 ++++
 src/test/modules/unsafe_tests/sql/rolenames.sql |  2 ++
 9 files changed, 44 insertions(+), 20 deletions(-)
 mode change 100644 => 100755 src/bin/pg_dump/t/010_dump_connstr.pl
 mode change 100644 => 100755 src/bin/scripts/t/020_createdb.pl

diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 87949054f26..a89604c3d52 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -742,6 +742,8 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	CreateDBStrategy dbstrategy = CREATEDB_WAL_LOG;
 	createdb_failure_params fparms;
 
+	reject_newline_in_name(dbname, "database");
+
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
 	{
@@ -1910,6 +1912,8 @@ RenameDatabase(const char *oldname, const char *newname)
 	int			npreparedxacts;
 	ObjectAddress address;
 
+	reject_newline_in_name(newname, "database");
+
 	/*
 	 * Look up the target database's OID, and get exclusive lock on it. We
 	 * need this for the same reasons as DROP DATABASE.
diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c
index 4172cc9bacb..bbd06ffd190 100644
--- a/src/backend/commands/define.c
+++ b/src/backend/commands/define.c
@@ -374,3 +374,20 @@ errorConflictingDefElem(DefElem *defel, ParseState *pstate)
 			errmsg("conflicting or redundant options"),
 			parser_errposition(pstate, defel->location));
 }
+
+/*
+ * reject_newline_in_name
+ *
+ * If name has a newline or carriage return character then error will be reported
+ * as these special characters are not allowed in names due to shell command error
+ * in dump.
+ */
+void
+reject_newline_in_name(const char *objname, const char *objtype)
+{
+	/* Report error if name has \n or \r character. */
+	if (strpbrk(objname, "\n\r"))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
+				errmsg("\"%s\" name \"%s\" contains a newline or carriage return character",objtype, objname));
+}
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 8fb9ea25db0..877c8236fab 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -171,6 +171,8 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
 	DefElem    *dbypassRLS = NULL;
 	GrantRoleOptions popt;
 
+	reject_newline_in_name(stmt->role, "role");
+
 	/* The defaults can vary depending on the original statement type */
 	switch (stmt->stmt_type)
 	{
@@ -1348,6 +1350,8 @@ RenameRole(const char *oldname, const char *newname)
 	ObjectAddress address;
 	Form_pg_authid authform;
 
+	reject_newline_in_name(newname, "role");
+
 	rel = table_open(AuthIdRelationId, RowExclusiveLock);
 	dsc = RelationGetDescr(rel);
 
diff --git a/src/bin/pg_dump/t/010_dump_connstr.pl b/src/bin/pg_dump/t/010_dump_connstr.pl
old mode 100644
new mode 100755
index dc7a33658db..bf2c3b6d00b
--- a/src/bin/pg_dump/t/010_dump_connstr.pl
+++ b/src/bin/pg_dump/t/010_dump_connstr.pl
@@ -153,20 +153,6 @@ $node->command_ok(
 	],
 	'pg_dumpall --dbname accepts connection string');
 
-$node->run_log(
-	[ 'createdb', '--username' => $src_bootstrap_super, "foo\n\rbar" ]);
-
-# not sufficient to use --roles-only here
-$node->command_fails(
-	[
-		'pg_dumpall', '--no-sync',
-		'--username' => $src_bootstrap_super,
-		'--file' => $discard,
-	],
-	'pg_dumpall with \n\r in database name');
-$node->run_log(
-	[ 'dropdb', '--username' => $src_bootstrap_super, "foo\n\rbar" ]);
-
 
 # make a table, so the parallel worker has something to dump
 $node->safe_psql(
diff --git a/src/bin/scripts/t/020_createdb.pl b/src/bin/scripts/t/020_createdb.pl
old mode 100644
new mode 100755
index 83b0077383a..18ff0254d59
--- a/src/bin/scripts/t/020_createdb.pl
+++ b/src/bin/scripts/t/020_createdb.pl
@@ -241,6 +241,18 @@ $node->command_fails(
 	],
 	'fails for invalid locale provider');
 
+$node->command_fails_like(
+    [ 'createdb', "invalid \n dbname" ],
+    qr(contains a newline or carriage return character),
+    'fails if database name containing newline character in name'
+);
+
+$node->command_fails_like(
+    [ 'createdb', "invalid \r dbname" ],
+    qr(contains a newline or carriage return character),,
+    'fails if database name containing carriage return character in name'
+);
+
 # Check use of templates with shared dependencies copied from the template.
 my ($ret, $stdout, $stderr) = $node->psql(
 	'foobar2',
diff --git a/src/fe_utils/string_utils.c b/src/fe_utils/string_utils.c
index 89ce396ed4f..38fffbd036b 100644
--- a/src/fe_utils/string_utils.c
+++ b/src/fe_utils/string_utils.c
@@ -568,12 +568,6 @@ appendByteaLiteral(PQExpBuffer buf, const unsigned char *str, size_t length,
  * Append the given string to the shell command being built in the buffer,
  * with shell-style quoting as needed to create exactly one argument.
  *
- * Forbid LF or CR characters, which have scant practical use beyond designing
- * security breaches.  The Windows command shell is unusable as a conduit for
- * arguments containing LF or CR characters.  A future major release should
- * reject those characters in CREATE ROLE and CREATE DATABASE, because use
- * there eventually leads to errors here.
- *
  * appendShellString() simply prints an error and dies if LF or CR appears.
  * appendShellStringNoError() omits those characters from the result, and
  * returns false if there were any.
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 8f4a2d9bbc1..bd930b8905d 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -162,5 +162,6 @@ extern TypeName *defGetTypeName(DefElem *def);
 extern int	defGetTypeLength(DefElem *def);
 extern List *defGetStringList(DefElem *def);
 pg_noreturn extern void errorConflictingDefElem(DefElem *defel, ParseState *pstate);
+extern void reject_newline_in_name(const char *objname, const char *objtype);
 
 #endif							/* DEFREM_H */
diff --git a/src/test/modules/unsafe_tests/expected/rolenames.out b/src/test/modules/unsafe_tests/expected/rolenames.out
index 61396b2a805..71c1d935091 100644
--- a/src/test/modules/unsafe_tests/expected/rolenames.out
+++ b/src/test/modules/unsafe_tests/expected/rolenames.out
@@ -102,6 +102,10 @@ DETAIL:  Role names starting with "pg_" are reserved.
 CREATE ROLE "pg_abcdef"; -- error
 ERROR:  role name "pg_abcdef" is reserved
 DETAIL:  Role names starting with "pg_" are reserved.
+CREATE ROLE "invalid
+rolename"; -- error
+ERROR:  "role" name "invalid
+rolename" contains a newline or carriage return character
 CREATE ROLE regress_testrol0 SUPERUSER LOGIN;
 CREATE ROLE regress_testrolx SUPERUSER LOGIN;
 CREATE ROLE regress_testrol2 SUPERUSER;
diff --git a/src/test/modules/unsafe_tests/sql/rolenames.sql b/src/test/modules/unsafe_tests/sql/rolenames.sql
index adac36536db..70b342abeb6 100644
--- a/src/test/modules/unsafe_tests/sql/rolenames.sql
+++ b/src/test/modules/unsafe_tests/sql/rolenames.sql
@@ -75,6 +75,8 @@ CREATE ROLE pg_abc; -- error
 CREATE ROLE "pg_abc"; -- error
 CREATE ROLE pg_abcdef; -- error
 CREATE ROLE "pg_abcdef"; -- error
+CREATE ROLE "invalid
+rolename"; -- error
 
 CREATE ROLE regress_testrol0 SUPERUSER LOGIN;
 CREATE ROLE regress_testrolx SUPERUSER LOGIN;
-- 
2.52.0

