From 8d4bcd2c773c159ae6e87c9bc7b9517bfb92835d Mon Sep 17 00:00:00 2001
From: Owen Williams <owen.williams@grafana.com>
Date: Tue, 3 Dec 2024 12:33:10 -0500
Subject: [PATCH] promql: Fix various UTF-8 bugs related to quoting

Fixes UTF-8 aggregator label list items getting mutated with quote marks when String-ified.
Fixes quoted metric names not supported in metric declarations.
Fixes UTF-8 label names not being quoted when String-ified.

Fixes https://github.com/prometheus/prometheus/issues/15470
Fixes https://github.com/prometheus/prometheus/issues/15528

Signed-off-by: Owen Williams <owen.williams@grafana.com>
Co-authored-by: Bryan Boreham <bjboreham@gmail.com>
---
 model/labels/labels_common.go       |   6 +-
 model/labels/labels_test.go         |   4 +
 promql/engine_test.go               |   2 +-
 promql/parser/generated_parser.y    |   4 +-
 promql/parser/generated_parser.y.go | 333 ++++++++++++++--------------
 promql/parser/parse.go              |   3 +-
 promql/parser/parse_test.go         |  80 ++++++-
 promql/parser/printer.go            |  17 +-
 promql/promqltest/test.go           |   4 +
 promql/promqltest/test_test.go      |  28 ++-
 storage/remote/codec_test.go        |   5 +
 11 files changed, 295 insertions(+), 191 deletions(-)

diff --git a/model/labels/labels_common.go b/model/labels/labels_common.go
index 99529a383..a232eeea5 100644
--- a/model/labels/labels_common.go
+++ b/model/labels/labels_common.go
@@ -51,7 +51,11 @@ func (ls Labels) String() string {
 			b.WriteByte(',')
 			b.WriteByte(' ')
 		}
-		b.WriteString(l.Name)
+		if !model.LabelName(l.Name).IsValidLegacy() {
+			b.Write(strconv.AppendQuote(b.AvailableBuffer(), l.Name))
+		} else {
+			b.WriteString(l.Name)
+		}
 		b.WriteByte('=')
 		b.Write(strconv.AppendQuote(b.AvailableBuffer(), l.Value))
 		i++
diff --git a/model/labels/labels_test.go b/model/labels/labels_test.go
index 3a4040776..06802d6f3 100644
--- a/model/labels/labels_test.go
+++ b/model/labels/labels_test.go
@@ -39,6 +39,10 @@ func TestLabels_String(t *testing.T) {
 			labels:   Labels{},
 			expected: "{}",
 		},
+		{
+			labels:   FromStrings("service.name", "t1", "whatever\\whatever", "t2"),
+			expected: `{"service.name"="t1", "whatever\\whatever"="t2"}`,
+		},
 	}
 	for _, c := range cases {
 		str := c.labels.String()
diff --git a/promql/engine_test.go b/promql/engine_test.go
index 8b8dc3909..20d78a7d8 100644
--- a/promql/engine_test.go
+++ b/promql/engine_test.go
@@ -751,7 +751,7 @@ load 10s
 			Interval: 5 * time.Second,
 		},
 		{
-			Query:       `count_values("wrong label!", metric)`,
+			Query:       `count_values("wrong label!\xff", metric)`,
 			ShouldError: true,
 		},
 	}
diff --git a/promql/parser/generated_parser.y b/promql/parser/generated_parser.y
index c321a1e97..3865dc654 100644
--- a/promql/parser/generated_parser.y
+++ b/promql/parser/generated_parser.y
@@ -669,14 +669,14 @@ label_set_item  : IDENTIFIER EQL STRING
                         { $$ = labels.Label{Name: $1.Val, Value: yylex.(*parser).unquoteString($3.Val) } }
                 | string_identifier EQL STRING
                         { $$ = labels.Label{Name: $1.Val, Value: yylex.(*parser).unquoteString($3.Val) } }
+                | string_identifier
+                        { $$ = labels.Label{Name: labels.MetricName, Value: $1.Val} }
                 | IDENTIFIER EQL error
                         { yylex.(*parser).unexpected("label set", "string"); $$ = labels.Label{}}
                 | string_identifier EQL error
                         { yylex.(*parser).unexpected("label set", "string"); $$ = labels.Label{}}
                 | IDENTIFIER error
                         { yylex.(*parser).unexpected("label set", "\"=\""); $$ = labels.Label{}}
-                | string_identifier error
-                        { yylex.(*parser).unexpected("label set", "\"=\""); $$ = labels.Label{}}
                 | error
                         { yylex.(*parser).unexpected("label set", "identifier or \"}\""); $$ = labels.Label{} }
                 ;
diff --git a/promql/parser/generated_parser.y.go b/promql/parser/generated_parser.y.go
index 8979410ce..7ff859116 100644
--- a/promql/parser/generated_parser.y.go
+++ b/promql/parser/generated_parser.y.go
@@ -339,7 +339,7 @@ var yyExca = [...]int16{
 	79, 197,
 	85, 197,
 	-2, 125,
-	-1, 205,
+	-1, 204,
 	9, 246,
 	12, 246,
 	13, 246,
@@ -371,7 +371,7 @@ var yyExca = [...]int16{
 	88, 246,
 	89, 246,
 	-2, 0,
-	-1, 206,
+	-1, 205,
 	9, 246,
 	12, 246,
 	13, 246,
@@ -407,139 +407,139 @@ var yyExca = [...]int16{
 
 const yyPrivate = 57344
 
-const yyLast = 804
+const yyLast = 803
 
 var yyAct = [...]int16{
-	155, 339, 337, 158, 344, 231, 39, 197, 281, 44,
-	296, 295, 84, 120, 82, 181, 109, 108, 351, 352,
-	353, 354, 107, 111, 203, 136, 204, 159, 154, 112,
-	205, 206, 234, 6, 271, 55, 163, 163, 107, 334,
-	333, 307, 244, 275, 309, 54, 162, 162, 250, 363,
-	91, 272, 330, 131, 362, 233, 60, 270, 276, 110,
-	100, 101, 298, 115, 103, 116, 106, 90, 164, 164,
-	114, 265, 113, 361, 277, 307, 360, 246, 247, 338,
-	103, 248, 106, 153, 165, 165, 264, 316, 201, 261,
-	122, 105, 235, 237, 239, 240, 241, 249, 251, 254,
-	255, 256, 257, 258, 262, 263, 273, 105, 236, 238,
-	242, 243, 245, 252, 253, 152, 117, 166, 259, 260,
-	176, 164, 170, 173, 163, 168, 223, 169, 172, 2,
-	3, 4, 5, 107, 162, 199, 111, 165, 187, 202,
-	189, 171, 112, 269, 207, 208, 209, 210, 211, 212,
-	213, 214, 215, 216, 217, 218, 219, 220, 221, 200,
-	89, 91, 113, 222, 123, 193, 268, 329, 224, 225,
-	183, 100, 101, 191, 121, 103, 104, 106, 90, 7,
-	85, 234, 266, 182, 55, 183, 328, 86, 192, 123,
-	83, 244, 122, 267, 54, 132, 190, 250, 188, 121,
-	345, 230, 105, 86, 233, 77, 35, 119, 304, 10,
-	185, 327, 86, 303, 293, 294, 157, 315, 297, 79,
-	184, 186, 326, 163, 274, 185, 246, 247, 302, 325,
-	248, 324, 314, 162, 323, 184, 186, 299, 261, 313,
-	322, 235, 237, 239, 240, 241, 249, 251, 254, 255,
-	256, 257, 258, 262, 263, 164, 321, 236, 238, 242,
-	243, 245, 252, 253, 180, 126, 320, 259, 260, 179,
-	125, 165, 305, 319, 306, 308, 318, 310, 317, 130,
-	88, 129, 178, 124, 311, 312, 137, 138, 139, 140,
+	154, 338, 336, 157, 343, 230, 39, 196, 280, 44,
+	295, 294, 84, 120, 82, 233, 180, 109, 108, 350,
+	351, 352, 353, 110, 111, 243, 202, 158, 203, 135,
+	112, 249, 361, 6, 333, 329, 113, 332, 232, 204,
+	205, 308, 271, 60, 130, 270, 297, 268, 162, 315,
+	156, 360, 153, 306, 359, 344, 200, 162, 161, 55,
+	245, 246, 222, 115, 247, 116, 107, 161, 269, 54,
+	267, 114, 260, 306, 182, 234, 236, 238, 239, 240,
+	248, 250, 253, 254, 255, 256, 257, 261, 262, 163,
+	122, 235, 237, 241, 242, 244, 251, 252, 192, 328,
+	111, 258, 259, 117, 190, 164, 112, 152, 103, 55,
+	106, 337, 77, 113, 184, 151, 35, 165, 327, 54,
+	175, 191, 169, 172, 183, 185, 167, 189, 168, 2,
+	3, 4, 5, 107, 198, 105, 159, 160, 201, 186,
+	188, 7, 326, 206, 207, 208, 209, 210, 211, 212,
+	213, 214, 215, 216, 217, 218, 219, 220, 199, 194,
+	89, 91, 221, 162, 264, 325, 197, 223, 224, 171,
+	200, 100, 101, 161, 162, 103, 104, 106, 90, 263,
+	233, 324, 170, 162, 161, 323, 362, 322, 321, 274,
+	243, 122, 266, 161, 131, 163, 249, 272, 123, 320,
+	229, 319, 105, 232, 275, 318, 163, 317, 121, 85,
+	316, 164, 163, 292, 293, 163, 265, 296, 129, 83,
+	276, 86, 164, 273, 10, 245, 246, 187, 164, 247,
+	88, 164, 86, 50, 79, 36, 298, 260, 1, 78,
+	234, 236, 238, 239, 240, 248, 250, 253, 254, 255,
+	256, 257, 261, 262, 123, 49, 235, 237, 241, 242,
+	244, 251, 252, 181, 121, 182, 258, 259, 128, 48,
+	127, 304, 119, 305, 307, 59, 309, 86, 9, 9,
+	47, 46, 134, 310, 311, 136, 137, 138, 139, 140,
 	141, 142, 143, 144, 145, 146, 147, 148, 149, 150,
-	151, 195, 160, 161, 50, 163, 36, 167, 198, 331,
-	78, 332, 201, 228, 55, 162, 85, 227, 1, 340,
-	341, 342, 336, 49, 54, 343, 83, 347, 346, 349,
-	348, 48, 226, 47, 81, 355, 356, 164, 55, 86,
-	357, 53, 77, 301, 56, 8, 359, 22, 54, 37,
-	55, 175, 46, 165, 57, 128, 135, 127, 45, 43,
-	54, 364, 300, 59, 133, 174, 9, 9, 42, 134,
-	75, 41, 40, 51, 196, 358, 18, 19, 278, 87,
-	20, 194, 229, 80, 350, 156, 76, 58, 232, 52,
-	118, 61, 62, 63, 64, 65, 66, 67, 68, 69,
-	70, 71, 72, 73, 74, 0, 0, 0, 13, 0,
-	0, 0, 24, 0, 30, 0, 0, 31, 32, 55,
-	38, 0, 53, 77, 0, 56, 280, 0, 22, 54,
-	0, 0, 0, 279, 0, 57, 0, 283, 284, 282,
-	289, 291, 288, 290, 285, 286, 287, 292, 0, 0,
-	0, 75, 0, 0, 0, 0, 0, 18, 19, 0,
-	0, 20, 0, 0, 0, 0, 0, 76, 0, 0,
-	0, 0, 61, 62, 63, 64, 65, 66, 67, 68,
-	69, 70, 71, 72, 73, 74, 0, 0, 0, 13,
-	0, 0, 0, 24, 0, 30, 0, 55, 31, 32,
-	53, 77, 0, 56, 335, 0, 22, 54, 0, 0,
-	0, 0, 0, 57, 0, 283, 284, 282, 289, 291,
-	288, 290, 285, 286, 287, 292, 0, 0, 0, 75,
-	0, 0, 0, 0, 0, 18, 19, 0, 0, 20,
-	0, 0, 0, 17, 77, 76, 0, 0, 0, 22,
+	45, 43, 132, 173, 179, 184, 166, 85, 330, 178,
+	331, 42, 133, 55, 41, 183, 185, 83, 339, 340,
+	341, 335, 177, 54, 342, 81, 346, 345, 348, 347,
+	86, 303, 40, 314, 354, 355, 302, 55, 51, 356,
+	53, 77, 300, 56, 195, 358, 22, 54, 313, 55,
+	174, 301, 227, 57, 8, 312, 226, 357, 37, 54,
+	363, 299, 126, 277, 87, 193, 228, 125, 80, 75,
+	349, 225, 155, 58, 231, 18, 19, 52, 118, 20,
+	124, 0, 0, 0, 0, 76, 0, 0, 0, 0,
 	61, 62, 63, 64, 65, 66, 67, 68, 69, 70,
 	71, 72, 73, 74, 0, 0, 0, 13, 0, 0,
-	0, 24, 0, 30, 0, 0, 31, 32, 18, 19,
-	0, 0, 20, 0, 0, 0, 17, 35, 0, 0,
-	0, 0, 22, 11, 12, 14, 15, 16, 21, 23,
-	25, 26, 27, 28, 29, 33, 34, 0, 0, 0,
-	13, 0, 0, 0, 24, 0, 30, 0, 0, 31,
-	32, 18, 19, 0, 0, 20, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 11, 12, 14, 15,
-	16, 21, 23, 25, 26, 27, 28, 29, 33, 34,
-	107, 0, 0, 13, 0, 0, 0, 24, 177, 30,
-	0, 0, 31, 32, 0, 0, 0, 0, 0, 107,
-	0, 0, 0, 0, 0, 0, 0, 89, 91, 92,
-	0, 93, 94, 95, 96, 97, 98, 99, 100, 101,
-	102, 0, 103, 104, 106, 90, 89, 91, 92, 0,
+	0, 24, 0, 30, 0, 0, 31, 32, 55, 38,
+	107, 53, 77, 0, 56, 279, 0, 22, 54, 0,
+	0, 0, 278, 0, 57, 0, 282, 283, 281, 288,
+	290, 287, 289, 284, 285, 286, 291, 0, 91, 0,
+	75, 0, 0, 0, 0, 0, 18, 19, 100, 101,
+	20, 0, 103, 0, 106, 90, 76, 0, 0, 0,
+	0, 61, 62, 63, 64, 65, 66, 67, 68, 69,
+	70, 71, 72, 73, 74, 0, 0, 0, 13, 105,
+	0, 0, 24, 0, 30, 0, 55, 31, 32, 53,
+	77, 0, 56, 334, 0, 22, 54, 0, 0, 0,
+	0, 0, 57, 0, 282, 283, 281, 288, 290, 287,
+	289, 284, 285, 286, 291, 0, 0, 0, 75, 0,
+	0, 0, 0, 0, 18, 19, 0, 0, 20, 0,
+	0, 0, 17, 77, 76, 0, 0, 0, 22, 61,
+	62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
+	72, 73, 74, 0, 0, 0, 13, 0, 0, 0,
+	24, 0, 30, 0, 0, 31, 32, 18, 19, 0,
+	0, 20, 0, 0, 0, 17, 35, 0, 0, 0,
+	0, 22, 11, 12, 14, 15, 16, 21, 23, 25,
+	26, 27, 28, 29, 33, 34, 0, 0, 0, 13,
+	0, 0, 0, 24, 0, 30, 0, 0, 31, 32,
+	18, 19, 0, 0, 20, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 11, 12, 14, 15, 16,
+	21, 23, 25, 26, 27, 28, 29, 33, 34, 107,
+	0, 0, 13, 0, 0, 0, 24, 176, 30, 0,
+	0, 31, 32, 0, 0, 0, 0, 0, 107, 0,
+	0, 0, 0, 0, 0, 0, 89, 91, 92, 0,
 	93, 94, 95, 96, 97, 98, 99, 100, 101, 102,
-	0, 103, 104, 106, 90, 107, 0, 0, 0, 105,
+	0, 103, 104, 106, 90, 89, 91, 92, 0, 93,
+	94, 95, 96, 97, 98, 99, 100, 101, 102, 0,
+	103, 104, 106, 90, 107, 0, 0, 0, 105, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 107, 0, 0, 0, 105, 0,
-	0, 0, 89, 91, 92, 0, 93, 94, 95, 0,
-	97, 98, 99, 100, 101, 102, 0, 103, 104, 106,
-	90, 89, 91, 92, 0, 93, 94, 0, 0, 97,
-	98, 0, 100, 101, 102, 0, 103, 104, 106, 90,
-	0, 0, 0, 0, 105, 0, 0, 0, 0, 0,
+	0, 0, 0, 107, 0, 0, 0, 105, 0, 0,
+	0, 89, 91, 92, 0, 93, 94, 95, 0, 97,
+	98, 99, 100, 101, 102, 0, 103, 104, 106, 90,
+	89, 91, 92, 0, 93, 94, 0, 0, 97, 98,
+	0, 100, 101, 102, 0, 103, 104, 106, 90, 0,
+	0, 0, 0, 105, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 105,
+	0, 0, 105,
 }
 
 var yyPact = [...]int16{
-	31, 169, 574, 574, 410, 531, -1000, -1000, -1000, 193,
+	31, 131, 573, 573, 409, 530, -1000, -1000, -1000, 103,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
-	-1000, -1000, -1000, -1000, -1000, 314, -1000, 278, -1000, 655,
+	-1000, -1000, -1000, -1000, -1000, 305, -1000, 228, -1000, 654,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
-	-1000, -1000, 57, 147, -1000, -1000, 488, -1000, 488, 192,
+	-1000, -1000, 21, 98, -1000, -1000, 487, -1000, 487, 99,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
-	-1000, -1000, -1000, -1000, -1000, -1000, -1000, 187, -1000, -1000,
-	263, -1000, -1000, 353, 277, -1000, -1000, 29, -1000, -53,
-	-53, -53, -53, -53, -53, -53, -53, -53, -53, -53,
-	-53, -53, -53, -53, -53, 26, 214, 305, 147, -56,
-	-1000, 126, 126, 329, -1000, 636, 24, -1000, 262, -1000,
-	-1000, 181, 166, -1000, -1000, 178, -1000, 171, -1000, 163,
-	-1000, 296, 488, -1000, -58, -50, -1000, 488, 488, 488,
-	488, 488, 488, 488, 488, 488, 488, 488, 488, 488,
-	488, 488, -1000, 175, -1000, -1000, 111, -1000, -1000, -1000,
-	-1000, -1000, -1000, -1000, 115, 115, 311, -1000, -1000, -1000,
-	-1000, 179, -1000, -1000, 64, -1000, 655, -1000, -1000, 162,
-	-1000, 141, -1000, -1000, -1000, -1000, -1000, 32, -1000, -1000,
-	-1000, -1000, -1000, -1000, -1000, 25, 80, 17, -1000, -1000,
-	-1000, 409, 8, 126, 126, 126, 126, 24, 24, 119,
-	119, 119, 720, 701, 119, 119, 720, 24, 24, 119,
-	24, 8, -1000, 40, -1000, -1000, -1000, 341, -1000, 206,
+	-1000, -1000, -1000, -1000, -1000, -1000, -1000, 252, -1000, -1000,
+	360, -1000, -1000, 266, 214, -1000, -1000, 20, -1000, -49,
+	-49, -49, -49, -49, -49, -49, -49, -49, -49, -49,
+	-49, -49, -49, -49, -49, 50, 48, 304, 98, -55,
+	-1000, 167, 167, 328, -1000, 635, 52, -1000, 302, -1000,
+	-1000, 261, 70, -1000, -1000, 207, -1000, 102, -1000, 96,
+	154, 487, -1000, -56, -41, -1000, 487, 487, 487, 487,
+	487, 487, 487, 487, 487, 487, 487, 487, 487, 487,
+	487, -1000, 100, -1000, -1000, 47, -1000, -1000, -1000, -1000,
+	-1000, -1000, -1000, 39, 39, 350, -1000, -1000, -1000, -1000,
+	178, -1000, -1000, 157, -1000, 654, -1000, -1000, 196, -1000,
+	45, -1000, -1000, -1000, -1000, -1000, 43, -1000, -1000, -1000,
+	-1000, -1000, -1000, -1000, 16, 171, 163, -1000, -1000, -1000,
+	408, 406, 167, 167, 167, 167, 52, 52, 119, 119,
+	119, 719, 700, 119, 119, 719, 52, 52, 119, 52,
+	406, -1000, 24, -1000, -1000, -1000, 340, -1000, 329, -1000,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
 	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000,
-	-1000, -1000, -1000, -1000, -1000, 488, -1000, -1000, -1000, -1000,
-	-1000, -1000, 56, 56, 18, 56, 72, 72, 215, 70,
-	-1000, -1000, 272, 270, 267, 260, 250, 234, 228, 225,
-	223, 216, 205, -1000, -1000, -1000, -1000, -1000, -1000, 165,
-	-1000, -1000, -1000, 30, -1000, 655, -1000, -1000, -1000, 56,
-	-1000, 14, 13, 487, -1000, -1000, -1000, 22, 27, 27,
-	27, 115, 186, 186, 22, 186, 22, -74, -1000, -1000,
-	-1000, -1000, -1000, 56, 56, -1000, -1000, -1000, 56, -1000,
-	-1000, -1000, -1000, -1000, -1000, 27, -1000, -1000, -1000, -1000,
-	-1000, -1000, -1000, -1000, -1000, -1000, -1000, -1000, 52, -1000,
-	28, -1000, -1000, -1000, -1000,
+	-1000, -1000, -1000, -1000, 487, -1000, -1000, -1000, -1000, -1000,
+	-1000, 34, 34, 15, 34, 40, 40, 331, 32, -1000,
+	-1000, 204, 201, 199, 195, 193, 182, 181, 179, 175,
+	159, 136, -1000, -1000, -1000, -1000, -1000, -1000, 97, -1000,
+	-1000, -1000, 13, -1000, 654, -1000, -1000, -1000, 34, -1000,
+	11, 8, 486, -1000, -1000, -1000, 54, 174, 174, 174,
+	39, 41, 41, 54, 41, 54, -73, -1000, -1000, -1000,
+	-1000, -1000, 34, 34, -1000, -1000, -1000, 34, -1000, -1000,
+	-1000, -1000, -1000, -1000, 174, -1000, -1000, -1000, -1000, -1000,
+	-1000, -1000, -1000, -1000, -1000, -1000, -1000, 30, -1000, 165,
+	-1000, -1000, -1000, -1000,
 }
 
 var yyPgo = [...]int16{
-	0, 390, 13, 389, 5, 15, 388, 363, 387, 385,
-	12, 384, 209, 345, 383, 14, 382, 10, 11, 381,
-	379, 7, 378, 8, 4, 375, 2, 1, 3, 374,
-	27, 0, 373, 372, 17, 195, 371, 369, 6, 368,
-	365, 16, 364, 56, 359, 9, 358, 356, 352, 333,
-	331, 323, 304, 318, 306,
+	0, 378, 13, 377, 5, 16, 374, 275, 373, 372,
+	12, 370, 224, 354, 368, 14, 366, 10, 11, 365,
+	364, 7, 363, 8, 4, 357, 2, 1, 3, 344,
+	27, 0, 338, 332, 18, 194, 314, 312, 6, 311,
+	303, 17, 302, 43, 301, 9, 300, 282, 281, 280,
+	269, 255, 233, 238, 235,
 }
 
 var yyR1 = [...]int8{
@@ -584,7 +584,7 @@ var yyR2 = [...]int8{
 	2, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 3, 4, 2, 0,
-	3, 1, 2, 3, 3, 3, 3, 2, 2, 1,
+	3, 1, 2, 3, 3, 1, 3, 3, 2, 1,
 	2, 0, 3, 2, 1, 1, 3, 1, 3, 4,
 	1, 3, 5, 5, 1, 1, 1, 4, 3, 3,
 	2, 3, 1, 2, 3, 3, 3, 3, 3, 3,
@@ -612,30 +612,30 @@ var yyChk = [...]int16{
 	52, 53, 54, 56, 57, 83, 58, 14, -34, -41,
 	2, 79, 85, 15, -41, -38, -38, -43, -1, 20,
 	-2, 12, -10, 2, 20, 7, 2, 4, 2, 4,
-	2, 24, -35, -42, -37, -47, 78, -35, -35, -35,
+	24, -35, -42, -37, -47, 78, -35, -35, -35, -35,
 	-35, -35, -35, -35, -35, -35, -35, -35, -35, -35,
-	-35, -35, -45, 57, 2, -31, -9, 2, -28, -30,
-	88, 89, 19, 9, 41, 57, -45, 2, -41, -34,
-	-17, 15, 2, -17, -40, 22, -38, 22, 20, 7,
-	2, -5, 2, 4, 54, 44, 55, -5, 20, -15,
-	25, 2, 25, 2, -19, 5, -29, -21, 12, -28,
-	-30, 16, -38, 82, 84, 80, 81, -38, -38, -38,
+	-35, -45, 57, 2, -31, -9, 2, -28, -30, 88,
+	89, 19, 9, 41, 57, -45, 2, -41, -34, -17,
+	15, 2, -17, -40, 22, -38, 22, 20, 7, 2,
+	-5, 2, 4, 54, 44, 55, -5, 20, -15, 25,
+	2, 25, 2, -19, 5, -29, -21, 12, -28, -30,
+	16, -38, 82, 84, 80, 81, -38, -38, -38, -38,
 	-38, -38, -38, -38, -38, -38, -38, -38, -38, -38,
-	-38, -38, -45, 15, -28, -28, 21, 6, 2, -16,
-	22, -4, -6, 25, 2, 62, 78, 63, 79, 64,
-	65, 66, 80, 81, 12, 82, 47, 48, 51, 67,
-	18, 68, 83, 84, 69, 70, 71, 72, 73, 88,
-	89, 59, 74, 75, 22, 7, 20, -2, 25, 2,
-	25, 2, 26, 26, -30, 26, 41, 57, -22, 24,
-	17, -23, 30, 28, 29, 35, 36, 37, 33, 31,
-	34, 32, 38, -17, -17, -18, -17, -18, 22, -45,
-	21, 2, 22, 7, 2, -38, -27, 19, -27, 26,
-	-27, -21, -21, 24, 17, 2, 17, 6, 6, 6,
-	6, 6, 6, 6, 6, 6, 6, 6, 21, 2,
-	22, -4, -27, 26, 26, 17, -23, -26, 57, -27,
-	-31, -31, -31, -28, -24, 14, -24, -26, -24, -26,
-	-11, 92, 93, 94, 95, -27, -27, -27, -25, -31,
-	24, 21, 2, 21, -31,
+	-38, -45, 15, -28, -28, 21, 6, 2, -16, 22,
+	-4, -6, 25, 2, 62, 78, 63, 79, 64, 65,
+	66, 80, 81, 12, 82, 47, 48, 51, 67, 18,
+	68, 83, 84, 69, 70, 71, 72, 73, 88, 89,
+	59, 74, 75, 22, 7, 20, -2, 25, 2, 25,
+	2, 26, 26, -30, 26, 41, 57, -22, 24, 17,
+	-23, 30, 28, 29, 35, 36, 37, 33, 31, 34,
+	32, 38, -17, -17, -18, -17, -18, 22, -45, 21,
+	2, 22, 7, 2, -38, -27, 19, -27, 26, -27,
+	-21, -21, 24, 17, 2, 17, 6, 6, 6, 6,
+	6, 6, 6, 6, 6, 6, 6, 21, 2, 22,
+	-4, -27, 26, 26, 17, -23, -26, 57, -27, -31,
+	-31, -31, -28, -24, 14, -24, -26, -24, -26, -11,
+	92, 93, 94, 95, -27, -27, -27, -25, -31, 24,
+	21, 2, 21, -31,
 }
 
 var yyDef = [...]int16{
@@ -647,35 +647,35 @@ var yyDef = [...]int16{
 	18, 19, 0, 108, 233, 234, 0, 244, 0, 85,
 	86, -2, -2, -2, -2, -2, -2, -2, -2, -2,
 	-2, -2, -2, -2, -2, 227, 228, 0, 5, 100,
-	0, 128, 131, 0, 0, 139, 245, 140, 144, 43,
+	0, 128, 131, 0, 135, 139, 245, 140, 144, 43,
 	43, 43, 43, 43, 43, 43, 43, 43, 43, 43,
 	43, 43, 43, 43, 43, 0, 0, 0, 0, 22,
 	23, 0, 0, 0, 61, 0, 83, 84, 0, 89,
-	91, 0, 95, 99, 126, 0, 132, 0, 137, 0,
-	138, 143, 0, 42, 47, 48, 44, 0, 0, 0,
+	91, 0, 95, 99, 126, 0, 132, 0, 138, 0,
+	143, 0, 42, 47, 48, 44, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 68, 0, 70, 71, 0, 73, 239, 240,
-	74, 75, 235, 236, 0, 0, 0, 82, 20, 21,
-	24, 0, 54, 25, 0, 63, 65, 67, 87, 0,
-	92, 0, 98, 229, 230, 231, 232, 0, 127, 130,
-	133, 135, 134, 136, 142, 145, 147, 150, 154, 155,
-	156, 0, 26, 0, 0, -2, -2, 27, 28, 29,
-	30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
-	40, 41, 69, 0, 237, 238, 76, 0, 81, 0,
-	53, 56, 58, 59, 60, 198, 199, 200, 201, 202,
-	203, 204, 205, 206, 207, 208, 209, 210, 211, 212,
-	213, 214, 215, 216, 217, 218, 219, 220, 221, 222,
-	223, 224, 225, 226, 62, 66, 88, 90, 93, 97,
-	94, 96, 0, 0, 0, 0, 0, 0, 0, 0,
-	160, 162, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 45, 46, 49, 247, 50, 72, 0,
-	78, 80, 51, 0, 57, 64, 146, 241, 148, 0,
-	151, 0, 0, 0, 158, 163, 159, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 77, 79,
-	52, 55, 149, 0, 0, 157, 161, 164, 0, 243,
-	165, 166, 167, 168, 169, 0, 170, 171, 172, 173,
-	174, 180, 181, 182, 183, 152, 153, 242, 0, 178,
-	0, 176, 179, 175, 177,
+	0, 68, 0, 70, 71, 0, 73, 239, 240, 74,
+	75, 235, 236, 0, 0, 0, 82, 20, 21, 24,
+	0, 54, 25, 0, 63, 65, 67, 87, 0, 92,
+	0, 98, 229, 230, 231, 232, 0, 127, 130, 133,
+	136, 134, 137, 142, 145, 147, 150, 154, 155, 156,
+	0, 26, 0, 0, -2, -2, 27, 28, 29, 30,
+	31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	41, 69, 0, 237, 238, 76, 0, 81, 0, 53,
+	56, 58, 59, 60, 198, 199, 200, 201, 202, 203,
+	204, 205, 206, 207, 208, 209, 210, 211, 212, 213,
+	214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
+	224, 225, 226, 62, 66, 88, 90, 93, 97, 94,
+	96, 0, 0, 0, 0, 0, 0, 0, 0, 160,
+	162, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 45, 46, 49, 247, 50, 72, 0, 78,
+	80, 51, 0, 57, 64, 146, 241, 148, 0, 151,
+	0, 0, 0, 158, 163, 159, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 77, 79, 52,
+	55, 149, 0, 0, 157, 161, 164, 0, 243, 165,
+	166, 167, 168, 169, 0, 170, 171, 172, 173, 174,
+	180, 181, 182, 183, 152, 153, 242, 0, 178, 0,
+	176, 179, 175, 177,
 }
 
 var yyTok1 = [...]int8{
@@ -1623,10 +1623,9 @@ yydefault:
 			yyVAL.label = labels.Label{Name: yyDollar[1].item.Val, Value: yylex.(*parser).unquoteString(yyDollar[3].item.Val)}
 		}
 	case 135:
-		yyDollar = yyS[yypt-3 : yypt+1]
+		yyDollar = yyS[yypt-1 : yypt+1]
 		{
-			yylex.(*parser).unexpected("label set", "string")
-			yyVAL.label = labels.Label{}
+			yyVAL.label = labels.Label{Name: labels.MetricName, Value: yyDollar[1].item.Val}
 		}
 	case 136:
 		yyDollar = yyS[yypt-3 : yypt+1]
@@ -1635,9 +1634,9 @@ yydefault:
 			yyVAL.label = labels.Label{}
 		}
 	case 137:
-		yyDollar = yyS[yypt-2 : yypt+1]
+		yyDollar = yyS[yypt-3 : yypt+1]
 		{
-			yylex.(*parser).unexpected("label set", "\"=\"")
+			yylex.(*parser).unexpected("label set", "string")
 			yyVAL.label = labels.Label{}
 		}
 	case 138:
diff --git a/promql/parser/parse.go b/promql/parser/parse.go
index 3113d18d5..9bf27264a 100644
--- a/promql/parser/parse.go
+++ b/promql/parser/parse.go
@@ -244,7 +244,8 @@ type seriesDescription struct {
 	values []SequenceValue
 }
 
-// ParseSeriesDesc parses the description of a time series.
+// ParseSeriesDesc parses the description of a time series. It is only used in
+// the PromQL testing framework code.
 func ParseSeriesDesc(input string) (labels labels.Labels, values []SequenceValue, err error) {
 	p := NewParser(input)
 	p.lex.seriesDesc = true
diff --git a/promql/parser/parse_test.go b/promql/parser/parse_test.go
index 0e5e2f638..3445fce06 100644
--- a/promql/parser/parse_test.go
+++ b/promql/parser/parse_test.go
@@ -2398,7 +2398,7 @@ var testExpr = []struct {
 		},
 	},
 	{
-		input: `sum by ("foo")({"some.metric"})`,
+		input: `sum by ("foo bar")({"some.metric"})`,
 		expected: &AggregateExpr{
 			Op: SUM,
 			Expr: &VectorSelector{
@@ -2406,14 +2406,14 @@ var testExpr = []struct {
 					MustLabelMatcher(labels.MatchEqual, model.MetricNameLabel, "some.metric"),
 				},
 				PosRange: posrange.PositionRange{
-					Start: 15,
-					End:   30,
+					Start: 19,
+					End:   34,
 				},
 			},
-			Grouping: []string{"foo"},
+			Grouping: []string{"foo bar"},
 			PosRange: posrange.PositionRange{
 				Start: 0,
-				End:   31,
+				End:   35,
 			},
 		},
 	},
@@ -4023,6 +4023,76 @@ func TestParseExpressions(t *testing.T) {
 	}
 }
 
+func TestParseSeriesDesc(t *testing.T) {
+	tests := []struct {
+		name           string
+		input          string
+		expectedLabels labels.Labels
+		expectedValues []SequenceValue
+		expectError    string
+	}{
+		{
+			name:           "empty string",
+			expectedLabels: labels.EmptyLabels(),
+			expectedValues: []SequenceValue{},
+		},
+		{
+			name:  "simple line",
+			input: `http_requests{job="api-server", instance="0", group="production"}`,
+			expectedLabels: labels.FromStrings(
+				"__name__", "http_requests",
+				"group", "production",
+				"instance", "0",
+				"job", "api-server",
+			),
+			expectedValues: []SequenceValue{},
+		},
+		{
+			name:  "label name characters that require quoting",
+			input: `{"http.requests", "service.name"="api-server", instance="0", group="canary"}		0+50x2`,
+			expectedLabels: labels.FromStrings(
+				"__name__", "http.requests",
+				"group", "canary",
+				"instance", "0",
+				"service.name", "api-server",
+			),
+			expectedValues: []SequenceValue{
+				{Value: 0, Omitted: false, Histogram: (*histogram.FloatHistogram)(nil)},
+				{Value: 50, Omitted: false, Histogram: (*histogram.FloatHistogram)(nil)},
+				{Value: 100, Omitted: false, Histogram: (*histogram.FloatHistogram)(nil)},
+			},
+		},
+		{
+			name:        "confirm failure on junk after identifier",
+			input:       `{"http.requests"xx}		0+50x2`,
+			expectError: `parse error: unexpected identifier "xx" in label set, expected "," or "}"`,
+		},
+		{
+			name:        "confirm failure on bare operator after identifier",
+			input:       `{"http.requests"=, x="y"}		0+50x2`,
+			expectError: `parse error: unexpected "," in label set, expected string`,
+		},
+		{
+			name:        "confirm failure on unterminated string identifier",
+			input:       `{"http.requests}		0+50x2`,
+			expectError: `parse error: unterminated quoted string`,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			l, v, err := ParseSeriesDesc(tc.input)
+			if tc.expectError != "" {
+				require.Contains(t, err.Error(), tc.expectError)
+			} else {
+				require.NoError(t, err)
+				require.True(t, labels.Equal(tc.expectedLabels, l))
+				require.Equal(t, tc.expectedValues, v)
+			}
+		})
+	}
+}
+
 // NaN has no equality. Thus, we need a separate test for it.
 func TestNaNExpression(t *testing.T) {
 	expr, err := ParseExpr("NaN")
diff --git a/promql/parser/printer.go b/promql/parser/printer.go
index 63b195082..afe755e7d 100644
--- a/promql/parser/printer.go
+++ b/promql/parser/printer.go
@@ -14,8 +14,10 @@
 package parser
 
 import (
+	"bytes"
 	"fmt"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 
@@ -91,13 +93,20 @@ func (node *AggregateExpr) getAggOpStr() string {
 }
 
 func joinLabels(ss []string) string {
+	var bytea [1024]byte // On stack to avoid memory allocation while building the output.
+	b := bytes.NewBuffer(bytea[:0])
+
 	for i, s := range ss {
-		// If the label is already quoted, don't quote it again.
-		if s[0] != '"' && s[0] != '\'' && s[0] != '`' && !model.IsValidLegacyMetricName(string(model.LabelValue(s))) {
-			ss[i] = fmt.Sprintf("\"%s\"", s)
+		if i > 0 {
+			b.WriteString(", ")
+		}
+		if !model.IsValidLegacyMetricName(string(model.LabelValue(s))) {
+			b.Write(strconv.AppendQuote(b.AvailableBuffer(), s))
+		} else {
+			b.WriteString(s)
 		}
 	}
-	return strings.Join(ss, ", ")
+	return b.String()
 }
 
 func (node *BinaryExpr) returnBool() string {
diff --git a/promql/promqltest/test.go b/promql/promqltest/test.go
index f208b4f31..60df00503 100644
--- a/promql/promqltest/test.go
+++ b/promql/promqltest/test.go
@@ -56,6 +56,10 @@ const (
 	DefaultMaxSamplesPerQuery = 10000
 )
 
+func init() {
+	model.NameValidationScheme = model.UTF8Validation
+}
+
 type TBRun interface {
 	testing.TB
 	Run(string, func(*testing.T)) bool
diff --git a/promql/promqltest/test_test.go b/promql/promqltest/test_test.go
index d0d09271e..327dcd78f 100644
--- a/promql/promqltest/test_test.go
+++ b/promql/promqltest/test_test.go
@@ -165,6 +165,8 @@ load 5m
 	http_requests{job="api-server", instance="1", group="production"}	0+20x10
 	http_requests{job="api-server", instance="0", group="canary"}		0+30x10
 	http_requests{job="api-server", instance="1", group="canary"}		0+40x10
+	{"http.requests", "service.name"="api-server", instance="0", group="canary"}		0+50x10
+	{"http.requests", "service.name"="api-server", instance="1", group="canary"}		0+60x10
 `
 
 	testCases := map[string]struct {
@@ -176,6 +178,12 @@ load 5m
 eval instant at 5m sum by (group) (http_requests)
 	{group="production"} 30
 	{group="canary"} 70
+`,
+		},
+		"instant query on UTF-8 metric with expected float result": {
+			input: testData + `
+eval instant at 5m sum by ("service.name") ({"http.requests"})
+	{"service.name"="api-server"} 110
 `,
 		},
 		"instant query with unexpected float result": {
@@ -184,7 +192,7 @@ eval instant at 5m sum by (group) (http_requests)
 	{group="production"} 30
 	{group="canary"} 80
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected 80 for {group="canary"} but got 70`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): expected 80 for {group="canary"} but got 70`,
 		},
 		"instant query with expected histogram result": {
 			input: `
@@ -230,7 +238,7 @@ eval instant at 0 testmetric
 eval instant at 5m sum by (group) (http_requests)
 	{group="production"} 30
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): unexpected metric {group="canary"} in result, has value 70`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): unexpected metric {group="canary"} in result, has value 70`,
 		},
 		"instant query, but result has an unexpected series with a histogram value": {
 			input: `
@@ -248,7 +256,7 @@ eval instant at 5m sum by (group) (http_requests)
 	{group="canary"} 70
 	{group="test"} 100
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected metric {group="test"} with 3: [100.000000] not found`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): expected metric {group="test"} with 3: [100.000000] not found`,
 		},
 		"instant query expected to fail, and query fails": {
 			input: `
@@ -334,7 +342,7 @@ eval_ordered instant at 50m sort(http_requests)
 	http_requests{group="canary", instance="1", job="api-server"} 400
 	http_requests{group="canary", instance="0", job="api-server"} 300
 `,
-			expectedError: `error in eval sort(http_requests) (line 8): expected metric {__name__="http_requests", group="canary", instance="0", job="api-server"} with [300.000000] at position 4 but was at 3`,
+			expectedError: `error in eval sort(http_requests) (line 10): expected metric {__name__="http_requests", group="canary", instance="0", job="api-server"} with [300.000000] at position 4 but was at 3`,
 		},
 		"instant query with results expected to match provided order, but result has an unexpected series": {
 			input: testData + `
@@ -343,7 +351,7 @@ eval_ordered instant at 50m sort(http_requests)
 	http_requests{group="production", instance="1", job="api-server"} 200
 	http_requests{group="canary", instance="0", job="api-server"} 300
 `,
-			expectedError: `error in eval sort(http_requests) (line 8): unexpected metric {__name__="http_requests", group="canary", instance="1", job="api-server"} in result, has value 400`,
+			expectedError: `error in eval sort(http_requests) (line 10): unexpected metric {__name__="http_requests", group="canary", instance="1", job="api-server"} in result, has value 400`,
 		},
 		"instant query with invalid timestamp": {
 			input:         `eval instant at abc123 vector(0)`,
@@ -362,7 +370,7 @@ eval range from 0 to 10m step 5m sum by (group) (http_requests)
 	{group="production"} 0 30 60
 	{group="canary"} 0 80 140
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected float value at index 1 (t=300000) for {group="canary"} to be 80, but got 70 (result has 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points [])`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): expected float value at index 1 (t=300000) for {group="canary"} to be 80, but got 70 (result has 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points [])`,
 		},
 		"range query with expected histogram values": {
 			input: `
@@ -389,7 +397,7 @@ eval range from 0 to 10m step 5m sum by (group) (http_requests)
 	{group="production"} 0 30 60 90
 	{group="canary"} 0 70 140
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected 4 points for {group="production"}, but query time range cannot return this many points`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): expected 4 points for {group="production"}, but query time range cannot return this many points`,
 		},
 		"range query with missing point in result": {
 			input: `
@@ -407,14 +415,14 @@ eval range from 0 to 10m step 5m sum by (group) (http_requests)
 	{group="production"} 0 30
 	{group="canary"} 0 70 140
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected 2 float points and 0 histogram points for {group="production"}, but got 3 float points [0 @[0] 30 @[300000] 60 @[600000]] and 0 histogram points []`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): expected 2 float points and 0 histogram points for {group="production"}, but got 3 float points [0 @[0] 30 @[300000] 60 @[600000]] and 0 histogram points []`,
 		},
 		"range query, but result has an unexpected series": {
 			input: testData + `
 eval range from 0 to 10m step 5m sum by (group) (http_requests)
 	{group="production"} 0 30 60
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): unexpected metric {group="canary"} in result, has 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points []`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): unexpected metric {group="canary"} in result, has 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points []`,
 		},
 		"range query, but result is missing a series": {
 			input: testData + `
@@ -423,7 +431,7 @@ eval range from 0 to 10m step 5m sum by (group) (http_requests)
 	{group="canary"} 0 70 140
 	{group="test"} 0 100 200
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected metric {group="test"} not found`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 10): expected metric {group="test"} not found`,
 		},
 		"range query expected to fail, and query fails": {
 			input: `
diff --git a/storage/remote/codec_test.go b/storage/remote/codec_test.go
index 35cd4c4cd..6fb1ae1e4 100644
--- a/storage/remote/codec_test.go
+++ b/storage/remote/codec_test.go
@@ -163,6 +163,11 @@ func TestWriteV2RequestFixture(t *testing.T) {
 }
 
 func TestValidateLabelsAndMetricName(t *testing.T) {
+	oldScheme := model.NameValidationScheme
+	model.NameValidationScheme = model.LegacyValidation
+	defer func() {
+		model.NameValidationScheme = oldScheme
+	}()
 	tests := []struct {
 		input       []prompb.Label
 		expectedErr string