From f5ef00aed4c39645716cabb2e4cf1ef3598fcde7 Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Wed, 25 Feb 2015 23:48:28 -0500
Subject: [PATCH] Free SQLSTATE and SQLERRM no earlier than other PL/pgSQL
variables.
"RETURN SQLERRM" prompted plpgsql_exec_function() to read from freed
memory. Back-patch to 9.0 (all supported versions). Little code ran
between the premature free and the read, so non-assert builds are
unlikely to witness user-visible consequences.
---
src/pl/plpgsql/src/pl_exec.c | 12 +++---------
src/test/regress/expected/plpgsql.out | 12 ++++++++++++
src/test/regress/sql/plpgsql.sql | 10 +++++++++-
3 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index b7e3bc42354..edcb230d5d5 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -1243,8 +1243,9 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
{
/*
* Initialize the magic SQLSTATE and SQLERRM variables for
- * the exception block. We needn't do this until we have
- * found a matching exception.
+ * the exception block; this also frees values from any
+ * prior use of the same exception. We needn't do this
+ * until we have found a matching exception.
*/
PLpgSQL_var *state_var;
PLpgSQL_var *errm_var;
@@ -1268,13 +1269,6 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
rc = exec_stmts(estate, exception->action);
- free_var(state_var);
- state_var->value = (Datum) 0;
- state_var->isnull = true;
- free_var(errm_var);
- errm_var->value = (Datum) 0;
- errm_var->isnull = true;
-
break;
}
}
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index daf3447915d..2c0b2e5e2b1 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2655,9 +2655,21 @@ NOTICE: P0001 user exception
(1 row)
+create function excpt_test4() returns text as $$
+begin
+ begin perform 1/0;
+ exception when others then return sqlerrm; end;
+end; $$ language plpgsql;
+select excpt_test4();
+ excpt_test4
+------------------
+ division by zero
+(1 row)
+
drop function excpt_test1();
drop function excpt_test2();
drop function excpt_test3();
+drop function excpt_test4();
-- parameters of raise stmt can be expressions
create function raise_exprs() returns void as $$
declare
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index a0840c9dc8d..001138eea28 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -2246,11 +2246,19 @@ begin
raise notice '% %', sqlstate, sqlerrm;
end;
end; $$ language plpgsql;
-
select excpt_test3();
+
+create function excpt_test4() returns text as $$
+begin
+ begin perform 1/0;
+ exception when others then return sqlerrm; end;
+end; $$ language plpgsql;
+select excpt_test4();
+
drop function excpt_test1();
drop function excpt_test2();
drop function excpt_test3();
+drop function excpt_test4();
-- parameters of raise stmt can be expressions
create function raise_exprs() returns void as $$
--
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