The escape QuoteIdent applies is not ours to choose — the datastore driver
already spells it, as colEscape/colUnEscape in hanzo-ds/go
lib/column/column.go. The test now asserts QuoteIdent writes exactly what the
driver would and that the driver's own inverse recovers the name, so if that
dialect ever moves this fails instead of quietly emitting an identifier the
server reads differently than we wrote it.
The comment claimed "order matters" between the two replacements. It does not,
and the claim was the dangerous kind of wrong: it invites someone to unroll the
Replacer into two sequential ReplaceAll calls and put them in the "right" order.
A Replacer is SINGLE PASS over non-overlapping patterns, so every input byte is
rewritten exactly once and order is irrelevant. Sequential ReplaceAll would be
the broken form — escaping the backtick first and the backslash second doubles
the backslashes the first call just introduced. Said plainly now, with the
warning attached to the thing it protects.
No behaviour change.
Co-authored-by: Hanzo Dev <[email protected]>
A telemetry field key name arrives as JSON on /api/v5/query_range and is
replayed out of stored dashboards and alert rules. It lands in two syntactic
positions and a bound parameter can occupy NEITHER:
- a backtick-quoted IDENTIFIER — the SELECT alias, the GROUP BY term, the
ORDER BY term;
- a single-quoted LITERAL — the accessors that read one attribute out of a
column, JSONExtractString(labels, '<name>') and friends.
Nothing quoted it. The rendering was written inline about forty times, always
as "`"+name+"`" or '%s', and the one call that sat next to a name —
sqlbuilder.Escape — replaces "$" with "$$" for the builder's own placeholder
syntax and is not SQL escaping. Measured against the real builder, a group-by
name of
le`,(select/**/grouparray(name)/**/from/**/system.tables)/**/as/**/`x
emitted that subquery as an ADDITIONAL SELECT COLUMN, whose rows come back in
the response body; "/**/" stands in for the spaces the builder strips and the
payload is all-lowercase so nothing folds it. A name carrying "'" breaks the
labels accessor the same way, and one ending in "\" eats whichever delimiter
closes it.
The request validator is not where this can be fixed. The rule evaluator builds
a QueryRangeRequest and calls the querier directly, so a stored rule's name
never meets it; and validateOrderBy, which does gate the DIRECTION strictly to
asc|desc, gates the sibling key NAME against an allowlist it builds out of the
caller's own GroupBy — so a name repeated in both fields validates itself.
Metrics settles it: a metric label is free-form, an unrecognised name falls back
to the labels column BY DESIGN, and there is no key allowlist to fail against.
So the guard goes where the name becomes text. QuoteIdent and EscapeLiteral are
the one renderer, in querybuilder, which every signal package already imports;
the ~40 inline spellings now call them. Both escape the backslash BEFORE the
delimiter, or a trailing backslash would consume the delimiter being added. A
name with none of those characters — every real attribute key, which is a dotted
identifier — renders byte for byte as it did, which is why the golden-SQL suites
in all six signal packages are unchanged.
The test asserts on emitted SQL and structurally rather than textually: the
payload MAY appear, quoted, as the inert name of a label nobody has, but it must
never appear in the executable skeleton — the text left once every quoted region
is removed. That is the property an injection breaks, so it fails if any layer
underneath stops escaping.
Co-authored-by: Hanzo Dev <[email protected]>
zeekay
