Hello everyone, I'd like to propose adding a check for the nullness of tuplestorestate before dereferencing it in src/backend/executor/nodeModifier.c. The patch is attached.
I am proposing this fix based on the assumption that tuplestorestate could be NULL since there is a check for it when calculating eof_tuplestore at line 85. However, since this code hasn't been changed since 2006 and hasn't caused any issues, it is possible that the check for (tuplestorestate == NULL) is redundant when calculating eof_tuplestore. -- Best regards, Alexander Kuznetsov
From b5217fd138f35fb5bf70ad8741ebed5330457891 Mon Sep 17 00:00:00 2001 From: Alexander Kuznetsov <kuznetso...@altlinux.org> Date: Thu, 10 Oct 2024 17:38:10 +0300 Subject: [PATCH] Check for tuplestorestate nullness before dereferencing tuplestorestate can be NULL when calculating eof_tuplestore, where tuplestorestate is dereferenced by tuplestore_gettuple(). Add check for nullness before dereferencing. Found by ALT Linux Team with Svace. --- src/backend/executor/nodeMaterial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c index 22e1787fbd..5bc8561f3a 100644 --- a/src/backend/executor/nodeMaterial.c +++ b/src/backend/executor/nodeMaterial.c @@ -95,7 +95,7 @@ ExecMaterial(PlanState *pstate) * to return the one before that, if possible. So do an extra * fetch. */ - if (!tuplestore_advance(tuplestorestate, forward)) + if (tuplestorestate == NULL || !tuplestore_advance(tuplestorestate, forward)) return NULL; /* the tuplestore must be empty */ } eof_tuplestore = false; -- 2.42.2
