pgsql: Fix Assert failure in XMLTABLE parser

Started by Richard Guoabout 1 year ago1 messagescomitters

rguo@postgresql.org

about 1 year ago

Fix Assert failure in XMLTABLE parser

In an XMLTABLE expression, columns can be marked NOT NULL, and the
parser internally fabricates an option named "is_not_null" to
represent this. However, the parser also allows users to specify
arbitrary option names. This creates a conflict: a user can
explicitly use "is_not_null" as an option name and assign it a
non-Boolean value, which violates internal assumptions and triggers an
assertion failure.

To fix, this patch checks whether a user-supplied name collides with
the internally reserved option name and raises an error if so.
Additionally, the internal name is renamed to "__pg__is_not_null" to
further reduce the risk of collision with user-defined names.

Reported-by: Евгений Горбанев <gorbanyoves@basealt.ru>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@kurilemu.de>
Discussion: /messages/by-id/6bac9886-65bf-4cec-96bd-e304159f28db@basealt.ru
Backpatch-through: 15

Branch
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REL_16_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/d3716d4b135756e38775a29a5ca26e17bd0efafc

Modified Files
--------------
src/backend/parser/gram.y | 15 +++++++++++----
src/test/regress/expected/xml.out | 4 ++++
src/test/regress/expected/xml_1.out | 4 ++++
src/test/regress/expected/xml_2.out | 4 ++++
src/test/regress/sql/xml.sql | 2 ++
5 files changed, 25 insertions(+), 4 deletions(-)