Fix handling of invalidly encoded data in escaping functions
authorAndres Freund <andres@anarazel.de>
Mon, 10 Feb 2025 15:03:40 +0000 (10:03 -0500)
committerAndres Freund <andres@anarazel.de>
Mon, 10 Feb 2025 15:03:40 +0000 (10:03 -0500)
commite0ef3d776a349db2c63075241626563b79477bd4
treefb63f0ad11fecb83f69b0eb1c502110121f2870f
parent2ae54ae17eaad592991e7459140b2cad2e82745c
Fix handling of invalidly encoded data in escaping functions

Previously invalidly encoded input to various escaping functions could lead to
the escaped string getting incorrectly parsed by psql.  To be safe, escaping
functions need to ensure that neither invalid nor incomplete multi-byte
characters can be used to "escape" from being quoted.

Functions which can report errors now return an error in more cases than
before. Functions that cannot report errors now replace invalid input bytes
with a byte sequence that cannot be used to escape the quotes and that is
guaranteed to error out when a query is sent to the server.

The following functions are fixed by this commit:
- PQescapeLiteral()
- PQescapeIdentifier()
- PQescapeString()
- PQescapeStringConn()
- fmtId()
- appendStringLiteral()

Reported-by: Stephen Fewer <stephen_fewer@rapid7.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Backpatch-through: 13
Security: CVE-2025-1094
src/fe_utils/string_utils.c
src/interfaces/libpq/fe-exec.c