The core of this patch is to prevent array_to_tsvector() from generating invalid tsvectors. It did not check for overly-long lexemes (so that WordEntry.len fields could overflow), nor did it check that the total "datalen" fits within MAXSTRPOS (so that WordEntry.pos fields could overflow, and the number of entries in the tsvector could be much more than the normal limit). While the field overflows couldn't do anything much worse than produce a corrupted tsvector value, a sufficiently large number of tsvector entries could cause integer overflows in later processing, such as tsvectorout. Another important fix is to prevent tsvectorrecv() from accepting invalid tsvectors. The main problem there is that it did not reject empty-string lexemes. Hence, even though it did (mostly) enforce the MAXSTRPOS limit, it could still produce a result with an unreasonable number of tsvector entries, if they were primarily empty strings. Also, fix tsvectorout's calculation of its required output buffer size: it was multiplying the string lengths by pg_database_encoding_max_length() for no reason. That contributed to the risk of integer overflow there. With valid tsvector input, there's no risk, but there's still no reason to make the output buffer several times bigger than needed. I also tried to make a couple of related routines more robust, and spent some effort on improving the comments in ts_type.h. Also, standardize on a single spelling of the "string is too long for tsvector" message, using %zu instead of an assortment of formats. These changes aren't security per se but came out of inspecting the code for problems. Reported-by: Yuhang Wu <yuhang@depthfirst.com> and Zhenpeng Lin Reported-by: Zheng Yu <zheng@depthfirst.com> Reported-by: Hcamael <baiyjrh@gmail.com> Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Backpatch-through: 14 Security: CVE-2026-14662
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/17/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/17/installation.html.
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