Avoid using unsafe search_path settings during dump and restore

Enterprise / PostgreSQL - Tom Lane [sss.pgh.pa.us] - 26 February 2018 15:18 EST

Historically, pg_dump has "set search_path = foo, pg_catalog" when dumping an object in schema "foo", and has also caused that setting to be used while restoring the object. This is problematic because functions and operators in schema "foo" could capture references meant to refer to pg_catalog entries, both in the queries issued by pg_dump and those issued during the subsequent restore run. That could result in dump/restore misbehavior, or in privilege escalation if a nefarious user installs trojan-horse functions or operators.

This patch changes pg_dump so that it does not change the search_path dynamically. The emitted restore script sets the search_path to what was used at dump time, and then leaves it alone thereafter. Created objects are placed in the correct schema, regardless of the active search_path, by dint of schema-qualifying their names in the CREATE commands, as well as in subsequent ALTER and ALTER-like commands.

Since this change requires a change in the behavior of pg_restore when processing an archive file made according to this new convention, bump the archive file version number; old versions of pg_restore will therefore refuse to process files made with new versions of pg_dump.

Security: CVE-2018-1058

3d2aed664e Avoid using unsafe search_path settings during dump and restore.
src/backend/utils/adt/ruleutils.c | 48 +-
src/bin/pg_dump/dumputils.c | 100 +-
src/bin/pg_dump/dumputils.h | 6 +-
src/bin/pg_dump/pg_backup.h | 3 +
src/bin/pg_dump/pg_backup_archiver.c | 53 +-
src/bin/pg_dump/pg_backup_archiver.h | 4 +-
src/bin/pg_dump/pg_dump.c | 1752 ++++++++--------------
src/bin/pg_dump/pg_dumpall.c | 34 +-
src/bin/pg_dump/t/002_pg_dump.pl | 384 ++---
src/test/modules/test_pg_dump/t/001_base.pl | 50 +-
src/test/regress/expected/collate.icu.utf8.out | 12 +-
src/test/regress/expected/collate.linux.utf8.out | 12 +-
src/test/regress/expected/collate.out | 12 +-
src/test/regress/expected/indexing.out | 98 +-
src/test/regress/expected/rules.out | 78 +-
src/test/regress/expected/triggers.out | 12 +-
16 files changed, 1166 insertions(+), 1492 deletions(-)

Upstream: git.postgresql.org

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