9146d0d650
transformAggregateCall() captures the datatypes of the aggregate's arguments immediately to construct the Aggref.aggargtypes list. This seems reasonable because the arguments have already been transformed --- but there is an edge case where they haven't been. Specifically, if we have an unknown-type literal in an ANY argument position, nothing will have been done with it earlier. But if we also have DISTINCT, then addTargetToGroupList() converts the literal to "text" type, resulting in the aggargtypes list not matching the actual runtime type of the argument. The end result is that the aggregate tries to interpret a "text" value as being of type "unknown", that is a zero-terminated C string. If the text value contains no zero bytes, this could result in disclosure of server memory following the text literal value. To fix, move the collection of the aggargtypes list to the end of transformAggregateCall(), after DISTINCT has been handled. This requires slightly more code, but not a great deal. Our thanks to Jingzhou Fu for reporting this problem. Security: CVE-2023-5868 |
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| .. | ||
| .gitignore | ||
| Makefile | ||
| README | ||
| analyze.c | ||
| check_keywords.pl | ||
| gram.y | ||
| parse_agg.c | ||
| parse_clause.c | ||
| parse_coerce.c | ||
| parse_collate.c | ||
| parse_cte.c | ||
| parse_enr.c | ||
| parse_expr.c | ||
| parse_func.c | ||
| parse_node.c | ||
| parse_oper.c | ||
| parse_param.c | ||
| parse_relation.c | ||
| parse_target.c | ||
| parse_type.c | ||
| parse_utilcmd.c | ||
| parser.c | ||
| scan.l | ||
| scansup.c | ||
README
src/backend/parser/README Parser ====== This directory does more than tokenize and parse SQL queries. It also creates Query structures for the various complex queries that are passed to the optimizer and then executor. parser.c things start here scan.l break query into tokens scansup.c handle escapes in input strings gram.y parse the tokens and produce a "raw" parse tree analyze.c top level of parse analysis for optimizable queries parse_agg.c handle aggregates, like SUM(col1), AVG(col2), ... parse_clause.c handle clauses like WHERE, ORDER BY, GROUP BY, ... parse_coerce.c handle coercing expressions to different data types parse_collate.c assign collation information in completed expressions parse_cte.c handle Common Table Expressions (WITH clauses) parse_expr.c handle expressions like col, col + 3, x = 3 or x = 4 parse_func.c handle functions, table.column and column identifiers parse_node.c create nodes for various structures parse_oper.c handle operators in expressions parse_param.c handle Params (for the cases used in the core backend) parse_relation.c support routines for tables and column handling parse_target.c handle the result list of the query parse_type.c support routines for data type handling parse_utilcmd.c parse analysis for utility commands (done at execution time) See also src/common/keywords.c, which contains the table of standard keywords and the keyword lookup function. We separated that out because various frontend code wants to use it too.