570e2fcc04
Both of the checks in DefineIndex() that can produce this error message have a guard against negative attribute numbers, but lack a guard to ensure that attno is non-zero. As a result, we can index off the beginning of the TupleDesc and read a garbage byte for attgenerated. If that byte happens to be 'v', we'll incorrectly produce the error mentioned above. The first call site is easy to hit: any attempt to create an expression index does so. The second one is not currently hit in the regression tests, but can be hit by something like CREATE INDEX ON some_table ((some_function(some_table))). Found by study of a test_plan_advice failure on buildfarm member skink, though this issue has nothing to do with test_plan_advice and seems to have only been revealed by happenstance. Backpatch-through: 18 Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: http://postgr.es/m/CA+TgmoacixUZVvi00hOjk_d9B4iYKswWP1gNqQ8Vfray-AcOCA@mail.gmail.com
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.