From 65c1106d8c5bea72b30c257d992c0d42f1b52440 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 17 Oct 2022 12:14:39 -0400 Subject: [PATCH] Reject non-ON-SELECT rules that are named "_RETURN". DefineQueryRewrite() has long required that ON SELECT rules be named "_RETURN". But we overlooked the converse case: we should forbid non-ON-SELECT rules that are named "_RETURN". In particular this prevents using CREATE OR REPLACE RULE to overwrite a view's _RETURN rule with some other kind of rule, thereby breaking the view. Per bug #17646 from Kui Liu. Back-patch to all supported branches. Discussion: https://postgr.es/m/17646-70c93cfa40365776@postgresql.org --- src/backend/rewrite/rewriteDefine.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c index c9788e538d..62c46e4384 100644 --- a/src/backend/rewrite/rewriteDefine.c +++ b/src/backend/rewrite/rewriteDefine.c @@ -532,6 +532,18 @@ DefineQueryRewrite(const char *rulename, RelationGetDescr(event_relation), false, false); } + + /* + * And finally, if it's not an ON SELECT rule then it must *not* be + * named _RETURN. This prevents accidentally or maliciously replacing + * a view's ON SELECT rule with some other kind of rule. + */ + if (strcmp(rulename, ViewSelectRuleName) == 0) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("non-view rule for \"%s\" must not be named \"%s\"", + RelationGetRelationName(event_relation), + ViewSelectRuleName))); } /*