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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 | cbeb455275138e6525912dd480c421864994c9c1 (patch) | |
| tree | 8fb550db596227379ffa40522149909fcb0548b6 /src | |
| parent | ebf52e9b753250a0be07375c8c5f290e87edef2f (diff) | |
| download | postgresql-cbeb455275138e6525912dd480c421864994c9c1.tar.gz postgresql-cbeb455275138e6525912dd480c421864994c9c1.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
Diffstat (limited to 'src')
| -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 a88e9252873..7968db21740 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -1696,8 +1696,13 @@ 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 |