From 0daeba0e927bfcb3d0ed9d510b84e555fc1e2741 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 1 Jul 2016 11:40:22 -0400
Subject: [PATCH] Be more paranoid in ruleutils.c's get_variable().
We were merely Assert'ing that the Var matched the RTE it's supposedly
from. But if the user passes incorrect information to pg_get_expr(),
the RTE might in fact not match; this led either to Assert failures
or core dumps, as reported by Chris Hanks in bug #14220. To fix, just
convert the Asserts to test-and-elog. Adjust an existing test-and-elog
elsewhere in the same function to be consistent in wording.
(If we really felt these were user-facing errors, we might promote them to
ereport's; but I can't convince myself that they're worth translating.)
Back-patch to 9.3; the problematic code doesn't exist before that, and
a quick check says that 9.2 doesn't crash on such cases.
Michael Paquier and Thomas Munro
Report: <20160629224349.1407.32667@wrigleys.postgresql.org>
---
src/backend/utils/adt/ruleutils.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index afc26d424fe..ffd2ca54e71 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -5967,7 +5967,8 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
- elog(ERROR, "bogus varattno for subquery var: %d", var->varattno);
+ elog(ERROR, "invalid attnum %d for relation \"%s\"",
+ var->varattno, rte->eref->aliasname);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
@@ -6028,9 +6029,13 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
else if (attnum > 0)
{
/* Get column name to use from the colinfo struct */
- Assert(attnum <= colinfo->num_cols);
+ if (attnum > colinfo->num_cols)
+ elog(ERROR, "invalid attnum %d for relation \"%s\"",
+ attnum, rte->eref->aliasname);
attname = colinfo->colnames[attnum - 1];
- Assert(attname != NULL);
+ if (attname == NULL) /* dropped column? */
+ elog(ERROR, "invalid attnum %d for relation \"%s\"",
+ attnum, rte->eref->aliasname);
}
else
{
--
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