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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2022-08-08 11:12:31 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2022-08-08 11:12:31 -0400 |
| commit | b9b21acc766db54d8c337d508d0fe2f5bf2daab0 (patch) | |
| tree | f1e302dbebbfb0ec7cc53f9bbfbd3ef91463c481 /src/backend/commands/foreigncmds.c | |
| parent | 7e29a79a46d30dc236d097825ab849158929d977 (diff) | |
| download | postgresql-b9b21acc766db54d8c337d508d0fe2f5bf2daab0.tar.gz postgresql-b9b21acc766db54d8c337d508d0fe2f5bf2daab0.zip | |
In extensions, don't replace objects not belonging to the extension.
Previously, if an extension script did CREATE OR REPLACE and there was
an existing object not belonging to the extension, it would overwrite
the object and adopt it into the extension. This is problematic, first
because the overwrite is probably unintentional, and second because we
didn't change the object's ownership. Thus a hostile user could create
an object in advance of an expected CREATE EXTENSION command, and would
then have ownership rights on an extension object, which could be
modified for trojan-horse-type attacks.
Hence, forbid CREATE OR REPLACE of an existing object unless it already
belongs to the extension. (Note that we've always forbidden replacing
an object that belongs to some other extension; only the behavior for
previously-free-standing objects changes here.)
For the same reason, also fail CREATE IF NOT EXISTS when there is
an existing object that doesn't belong to the extension.
Our thanks to Sven Klemm for reporting this problem.
Security: CVE-2022-2625
Diffstat (limited to 'src/backend/commands/foreigncmds.c')
| -rw-r--r-- | src/backend/commands/foreigncmds.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c index ea27857bb84..91f4dd30de1 100644 --- a/src/backend/commands/foreigncmds.c +++ b/src/backend/commands/foreigncmds.c @@ -855,13 +855,22 @@ CreateForeignServer(CreateForeignServerStmt *stmt) ownerId = GetUserId(); /* - * Check that there is no other foreign server by this name. Do nothing if - * IF NOT EXISTS was enforced. + * Check that there is no other foreign server by this name. If there is + * one, do nothing if IF NOT EXISTS was specified. */ - if (GetForeignServerByName(stmt->servername, true) != NULL) + srvId = get_foreign_server_oid(stmt->servername, true); + if (OidIsValid(srvId)) { if (stmt->if_not_exists) { + /* + * If we are in an extension script, insist that the pre-existing + * object be a member of the extension, to avoid security risks. + */ + ObjectAddressSet(myself, ForeignServerRelationId, srvId); + checkMembershipInCurrentExtension(&myself); + + /* OK to skip */ ereport(NOTICE, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("server \"%s\" already exists, skipping", @@ -1126,6 +1135,10 @@ CreateUserMapping(CreateUserMappingStmt *stmt) { if (stmt->if_not_exists) { + /* + * Since user mappings aren't members of extensions (see comments + * below), no need for checkMembershipInCurrentExtension here. + */ ereport(NOTICE, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("user mapping for \"%s\" already exists for server \"%s\", skipping", |