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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2024-02-23 15:21:53 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2024-02-23 15:21:53 -0500 |
| commit | ef0333e6763349b0553dad296cd88a82207d1348 (patch) | |
| tree | 5d935d9baae2ed862ede75bb078b0f459a31837c | |
| parent | a6155c43cc82af2816af563704c9dcb78b09a779 (diff) | |
| download | postgresql-ef0333e6763349b0553dad296cd88a82207d1348.tar.gz postgresql-ef0333e6763349b0553dad296cd88a82207d1348.zip | |
Avoid dangling-pointer problem with partitionwise joins under GEQO.
build_child_join_sjinfo creates a derived SpecialJoinInfo in
the short-lived GEQO context, but afterwards the semi_rhs_exprs
from that may be used in a UniquePath for a child base relation.
This breaks the expectation that all base-relation-level structures
are in the planning-lifespan context, leading to use of a dangling
pointer with probable ensuing crash later on in create_unique_plan.
To fix, copy the expression trees when making a UniquePath.
Per bug #18360 from Alexander Lakhin. This has been broken since
partitionwise joins were added, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/18360-a23caf3157f34e62@postgresql.org
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 841be378dea..bd232263b48 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -1708,8 +1708,13 @@ create_unique_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, pathnode->path.pathkeys = NIL; pathnode->subpath = subpath; - pathnode->in_operators = sjinfo->semi_operators; - pathnode->uniq_exprs = sjinfo->semi_rhs_exprs; + + /* + * Under GEQO, the sjinfo might be short-lived, so we'd better make copies + * of data structures we extract from it. + */ + pathnode->in_operators = copyObject(sjinfo->semi_operators); + pathnode->uniq_exprs = copyObject(sjinfo->semi_rhs_exprs); /* * If the input is a relation and it has a unique index that proves the |