From: Richard Guo Date: Thu, 15 May 2025 08:09:04 +0000 (+0900) Subject: Fix Assert failure in XMLTABLE parser X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=666103090f1d18e26388aef1ee5840d86cb8604b;p=thirdparty%2Fpostgresql.git 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 Author: Richard Guo Reviewed-by: Alvaro Herrera Discussion: https://postgr.es/m/6bac9886-65bf-4cec-96bd-e304159f28db@basealt.ru Backpatch-through: 15 --- diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 8379e48c97b..c77060c2cea 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -13820,7 +13820,7 @@ xmltable_column_el: parser_errposition(defel->location))); fc->colexpr = defel->arg; } - else if (strcmp(defel->defname, "is_not_null") == 0) + else if (strcmp(defel->defname, "__pg__is_not_null") == 0) { if (nullability_seen) ereport(ERROR, @@ -13863,13 +13863,20 @@ xmltable_column_option_list: xmltable_column_option_el: IDENT b_expr - { $$ = makeDefElem($1, $2, @1); } + { + if (strcmp($1, "__pg__is_not_null") == 0) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("option name \"%s\" cannot be used in XMLTABLE", $1), + parser_errposition(@1))); + $$ = makeDefElem($1, $2, @1); + } | DEFAULT b_expr { $$ = makeDefElem("default", $2, @1); } | NOT NULL_P - { $$ = makeDefElem("is_not_null", (Node *) makeBoolean(true), @1); } + { $$ = makeDefElem("__pg__is_not_null", (Node *) makeBoolean(true), @1); } | NULL_P - { $$ = makeDefElem("is_not_null", (Node *) makeBoolean(false), @1); } + { $$ = makeDefElem("__pg__is_not_null", (Node *) makeBoolean(false), @1); } ; xml_namespace_list: diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out index f9b7ec0bab8..79054b75311 100644 --- a/src/test/regress/expected/xml.out +++ b/src/test/regress/expected/xml.out @@ -1139,6 +1139,10 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); ERROR: XMLTABLE function has 1 columns available but 2 columns specified +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); +ERROR: option name "__pg__is_not_null" cannot be used in XMLTABLE +LINE 1: ...MLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_n... + ^ -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out index 5b28ea01eea..abf27626a21 100644 --- a/src/test/regress/expected/xml_1.out +++ b/src/test/regress/expected/xml_1.out @@ -876,6 +876,10 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); ERROR: XMLTABLE function has 1 columns available but 2 columns specified +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); +ERROR: option name "__pg__is_not_null" cannot be used in XMLTABLE +LINE 1: ...MLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_n... + ^ -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out index 044a4917d86..23e0c14a2d2 100644 --- a/src/test/regress/expected/xml_2.out +++ b/src/test/regress/expected/xml_2.out @@ -1125,6 +1125,10 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); ERROR: XMLTABLE function has 1 columns available but 2 columns specified +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); +ERROR: option name "__pg__is_not_null" cannot be used in XMLTABLE +LINE 1: ...MLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_n... + ^ -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql index e908b6c3957..83c5b73d8d3 100644 --- a/src/test/regress/sql/xml.sql +++ b/src/test/regress/sql/xml.sql @@ -387,6 +387,8 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); + -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row'