51fed14d73
If a WAL record header was split across pages, but xl_tot_len was 0, we would get confused and conclude that we had already read the whole record, and proceed to CRC check it. That can lead to a crash in RecordIsValid(), which isn't careful to not read beyond end-of-record, as defined by xl_tot_len. Add an explicit sanity check for xl_tot_len <= SizeOfXlogRecord. Also, make RecordIsValid() more robust by checking in each step that it doesn't try to access memory beyond end of record, even if a length field in the record's or a backup block's header is bogus. Per report and analysis by Tom Lane.
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. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Changes between all PostgreSQL releases are recorded in the file HISTORY. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.