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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2023-01-02 16:17:00 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2023-01-02 16:17:00 -0500 |
| commit | a02740e53fb7d1668e2d0ea1362743d23211d43d (patch) | |
| tree | 5fe1a0d9364d9ea99f8922b4f249cfcc2a3bc904 | |
| parent | fdaba0a2d749bff497313b584f86855a1440d43e (diff) | |
| download | postgresql-a02740e53fb7d1668e2d0ea1362743d23211d43d.tar.gz postgresql-a02740e53fb7d1668e2d0ea1362743d23211d43d.zip | |
Avoid reference to nonexistent array element in ExecInitAgg().
When considering an empty grouping set, we fetched
phasedata->eqfunctions[-1]. Because the eqfunctions array is
palloc'd, that would always be an aset pointer in released versions,
and thus the code accidentally failed to malfunction (since it would
do nothing unless it found a null pointer). Nonetheless this seems
like trouble waiting to happen, so add a check for length == 0.
It's depressing that our valgrind testing did not catch this.
Maybe we should reconsider the choice to not mark that word NOACCESS?
Richard Guo
Discussion: https://postgr.es/m/CAMbWs4-vZuuPOZsKOYnSAaPYGKhmacxhki+vpOKk0O7rymccXQ@mail.gmail.com
| -rw-r--r-- | src/backend/executor/nodeAgg.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index 31609c60fc6..1fdfbd1eea7 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -3574,6 +3574,11 @@ ExecInitAgg(Agg *node, EState *estate, int eflags) { int length = phasedata->gset_lengths[i]; + /* nothing to do for empty grouping set */ + if (length == 0) + continue; + + /* if we already had one of this length, it'll do */ if (phasedata->eqfunctions[length - 1] != NULL) continue; |