vendor: bump gopkg.in/yaml.v2 v2.2.8

full diff: https://github.com/go-yaml/yaml/compare/v2.2.3...v2.2.8

includes:

- go-yaml/yaml 515 Improve heuristics preventing CPU/memory abuse
- go-yaml/yaml@f90ceb4f40 Fix check for non-map alias merging in v2
    - fix for "yaml.Unmarshal crashes on "assignment to entry in nil map""
- go-yaml/yaml 543 Port stale simple_keys fix to v2
- go-yaml/yaml@1f64d6156d Fix issue in simple_keys improvements
    - fixes "Invalid simple_keys now cause panics later in decode"
- go-yaml/yaml 555 Optimize cases with long potential simple_keys

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 3dfcfbb2bf)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor.conf

@@ -89,7 +89,7 @@ golang.org/x/time                                   fbb02b2291d28baffd63558aa44b
 google.golang.org/genproto                          02b4e95473316948020af0b7a4f0f22c73929b0e
 google.golang.org/grpc                              39e8a7b072a67ca2a75f57fa2e0d50995f5b22f6 # v1.23.1
 gopkg.in/inf.v0                                     d2d2541c53f18d2a059457998ce2876cc8e67cbf # v0.9.1
-gopkg.in/yaml.v2                                    bb4e33bf68bf89cad44d386192cbed201f35b241 # v2.2.3
+gopkg.in/yaml.v2                                    53403b58ad1b561927d19068c655246f2db79d48 # v2.2.8
 gotest.tools/v3                                     ab4a870b92ce57a83881fbeb535a137a20d664b7 # v3.0.1
 k8s.io/api                                          40a48860b5abbba9aa891b02b32da429b08d96a0 # kubernetes-1.14.0
 k8s.io/apimachinery                                 d7deff9243b165ee192f5551710ea4285dcfd615 # kubernetes-1.14.0

vendor/gopkg.in/yaml.v2/decode.go

@@ -318,12 +318,41 @@ func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unm
 	return out, false, false
 }
 
+const (
+	// 400,000 decode operations is ~500kb of dense object declarations, or
+	// ~5kb of dense object declarations with 10000% alias expansion
+	alias_ratio_range_low = 400000
+
+	// 4,000,000 decode operations is ~5MB of dense object declarations, or
+	// ~4.5MB of dense object declarations with 10% alias expansion
+	alias_ratio_range_high = 4000000
+
+	// alias_ratio_range is the range over which we scale allowed alias ratios
+	alias_ratio_range = float64(alias_ratio_range_high - alias_ratio_range_low)
+)
+
+func allowedAliasRatio(decodeCount int) float64 {
+	switch {
+	case decodeCount <= alias_ratio_range_low:
+		// allow 99% to come from alias expansion for small-to-medium documents
+		return 0.99
+	case decodeCount >= alias_ratio_range_high:
+		// allow 10% to come from alias expansion for very large documents
+		return 0.10
+	default:
+		// scale smoothly from 99% down to 10% over the range.
+		// this maps to 396,000 - 400,000 allowed alias-driven decodes over the range.
+		// 400,000 decode operations is ~100MB of allocations in worst-case scenarios (single-item maps).
+		return 0.99 - 0.89*(float64(decodeCount-alias_ratio_range_low)/alias_ratio_range)
+	}
+}
+
 func (d *decoder) unmarshal(n *node, out reflect.Value) (good bool) {
 	d.decodeCount++
 	if d.aliasDepth > 0 {
 		d.aliasCount++
 	}
-	if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > 0.99 {
+	if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > allowedAliasRatio(d.decodeCount) {
 		failf("document contains excessive aliasing")
 	}
 	switch n.kind {
@@ -759,8 +788,7 @@ func (d *decoder) merge(n *node, out reflect.Value) {
 	case mappingNode:
 		d.unmarshal(n, out)
 	case aliasNode:
-		an, ok := d.doc.anchors[n.value]
+		if n.alias != nil && n.alias.kind != mappingNode {
-		if ok && an.kind != mappingNode {
 			failWantMap()
 		}
 		d.unmarshal(n, out)
@@ -769,8 +797,7 @@ func (d *decoder) merge(n *node, out reflect.Value) {
 		for i := len(n.children) - 1; i >= 0; i-- {
 			ni := n.children[i]
 			if ni.kind == aliasNode {
-				an, ok := d.doc.anchors[ni.value]
+				if ni.alias != nil && ni.alias.kind != mappingNode {
-				if ok && an.kind != mappingNode {
 					failWantMap()
 				}
 			} else if ni.kind != mappingNode {

vendor/gopkg.in/yaml.v2/scannerc.go

@@ -626,31 +626,18 @@ func trace(args ...interface{}) func() {
 func yaml_parser_fetch_more_tokens(parser *yaml_parser_t) bool {
 	// While we need more tokens to fetch, do it.
 	for {
-		// Check if we really need to fetch more tokens.
+		if parser.tokens_head != len(parser.tokens) {
-		need_more_tokens := false
+			// If queue is non-empty, check if any potential simple key may
-
+			// occupy the head position.
-		if parser.tokens_head == len(parser.tokens) {
+			head_tok_idx, ok := parser.simple_keys_by_tok[parser.tokens_parsed]
-			// Queue is empty.
+			if !ok {
-			need_more_tokens = true
+				break
-		} else {
+			} else if valid, ok := yaml_simple_key_is_valid(parser, &parser.simple_keys[head_tok_idx]); !ok {
-			// Check if any potential simple key may occupy the head position.
-			if !yaml_parser_stale_simple_keys(parser) {
 				return false
-			}
+			} else if !valid {
-
-			for i := range parser.simple_keys {
-				simple_key := &parser.simple_keys[i]
-				if simple_key.possible && simple_key.token_number == parser.tokens_parsed {
-					need_more_tokens = true
 				break
 			}
 		}
-		}
-
-		// We are finished.
-		if !need_more_tokens {
-			break
-		}
 		// Fetch the next token.
 		if !yaml_parser_fetch_next_token(parser) {
 			return false
@@ -678,11 +665,6 @@ func yaml_parser_fetch_next_token(parser *yaml_parser_t) bool {
 		return false
 	}
 
-	// Remove obsolete potential simple keys.
-	if !yaml_parser_stale_simple_keys(parser) {
-		return false
-	}
-
 	// Check the indentation level against the current column.
 	if !yaml_parser_unroll_indent(parser, parser.mark.column) {
 		return false
@@ -837,29 +819,30 @@ func yaml_parser_fetch_next_token(parser *yaml_parser_t) bool {
 		"found character that cannot start any token")
 }
 
-// Check the list of potential simple keys and remove the positions that
+func yaml_simple_key_is_valid(parser *yaml_parser_t, simple_key *yaml_simple_key_t) (valid, ok bool) {
-// cannot contain simple keys anymore.
+	if !simple_key.possible {
-func yaml_parser_stale_simple_keys(parser *yaml_parser_t) bool {
+		return false, true
-	// Check for a potential simple key for each flow level.
+	}
-	for i := range parser.simple_keys {
-		simple_key := &parser.simple_keys[i]
 
-		// The specification requires that a simple key
+	// The 1.2 specification says:
 	//
-		//  - is limited to a single line,
+	//     "If the ? indicator is omitted, parsing needs to see past the
-		//  - is shorter than 1024 characters.
+	//     implicit key to recognize it as such. To limit the amount of
-		if simple_key.possible && (simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index) {
+	//     lookahead required, the “:” indicator must appear at most 1024
-
+	//     Unicode characters beyond the start of the key. In addition, the key
+	//     is restricted to a single line."
+	//
+	if simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index {
 		// Check if the potential simple key to be removed is required.
 		if simple_key.required {
-				return yaml_parser_set_scanner_error(parser,
+			return false, yaml_parser_set_scanner_error(parser,
 				"while scanning a simple key", simple_key.mark,
 				"could not find expected ':'")
 		}
 		simple_key.possible = false
+		return false, true
 	}
-	}
+	return true, true
-	return true
 }
 
 // Check if a simple key may start at the current position and add it if
@@ -879,13 +862,14 @@ func yaml_parser_save_simple_key(parser *yaml_parser_t) bool {
 			possible:     true,
 			required:     required,
 			token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+			mark:         parser.mark,
 		}
-		simple_key.mark = parser.mark
 
 		if !yaml_parser_remove_simple_key(parser) {
 			return false
 		}
 		parser.simple_keys[len(parser.simple_keys)-1] = simple_key
+		parser.simple_keys_by_tok[simple_key.token_number] = len(parser.simple_keys) - 1
 	}
 	return true
 }
@@ -900,19 +884,33 @@ func yaml_parser_remove_simple_key(parser *yaml_parser_t) bool {
 				"while scanning a simple key", parser.simple_keys[i].mark,
 				"could not find expected ':'")
 		}
-	}
 		// Remove the key from the stack.
 		parser.simple_keys[i].possible = false
+		delete(parser.simple_keys_by_tok, parser.simple_keys[i].token_number)
+	}
 	return true
 }
 
+// max_flow_level limits the flow_level
+const max_flow_level = 10000
+
 // Increase the flow level and resize the simple key list if needed.
 func yaml_parser_increase_flow_level(parser *yaml_parser_t) bool {
 	// Reset the simple key on the next level.
-	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{
+		possible:     false,
+		required:     false,
+		token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+		mark:         parser.mark,
+	})
 
 	// Increase the flow level.
 	parser.flow_level++
+	if parser.flow_level > max_flow_level {
+		return yaml_parser_set_scanner_error(parser,
+			"while increasing flow level", parser.simple_keys[len(parser.simple_keys)-1].mark,
+			fmt.Sprintf("exceeded max depth of %d", max_flow_level))
+	}
 	return true
 }
 
@@ -920,11 +918,16 @@ func yaml_parser_increase_flow_level(parser *yaml_parser_t) bool {
 func yaml_parser_decrease_flow_level(parser *yaml_parser_t) bool {
 	if parser.flow_level > 0 {
 		parser.flow_level--
-		parser.simple_keys = parser.simple_keys[:len(parser.simple_keys)-1]
+		last := len(parser.simple_keys) - 1
+		delete(parser.simple_keys_by_tok, parser.simple_keys[last].token_number)
+		parser.simple_keys = parser.simple_keys[:last]
 	}
 	return true
 }
 
+// max_indents limits the indents stack size
+const max_indents = 10000
+
 // Push the current indentation level to the stack and set the new level
 // the current column is greater than the indentation level.  In this case,
 // append or insert the specified token into the token queue.
@@ -939,6 +942,11 @@ func yaml_parser_roll_indent(parser *yaml_parser_t, column, number int, typ yaml
 		// indentation level.
 		parser.indents = append(parser.indents, parser.indent)
 		parser.indent = column
+		if len(parser.indents) > max_indents {
+			return yaml_parser_set_scanner_error(parser,
+				"while increasing indent level", parser.simple_keys[len(parser.simple_keys)-1].mark,
+				fmt.Sprintf("exceeded max depth of %d", max_indents))
+		}
 
 		// Create a token and insert it into the queue.
 		token := yaml_token_t{
@@ -989,6 +997,8 @@ func yaml_parser_fetch_stream_start(parser *yaml_parser_t) bool {
 	// Initialize the simple key stack.
 	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
 
+	parser.simple_keys_by_tok = make(map[int]int)
+
 	// A simple key is allowed at the beginning of the stream.
 	parser.simple_key_allowed = true
 
@@ -1270,7 +1280,11 @@ func yaml_parser_fetch_value(parser *yaml_parser_t) bool {
 	simple_key := &parser.simple_keys[len(parser.simple_keys)-1]
 
 	// Have we found a simple key?
-	if simple_key.possible {
+	if valid, ok := yaml_simple_key_is_valid(parser, simple_key); !ok {
+		return false
+
+	} else if valid {
+
 		// Create the KEY token and insert it into the queue.
 		token := yaml_token_t{
 			typ:        yaml_KEY_TOKEN,
@@ -1288,6 +1302,7 @@ func yaml_parser_fetch_value(parser *yaml_parser_t) bool {
 
 		// Remove the simple key.
 		simple_key.possible = false
+		delete(parser.simple_keys_by_tok, simple_key.token_number)
 
 		// A simple key cannot follow another simple key.
 		parser.simple_key_allowed = false

vendor/gopkg.in/yaml.v2/yaml.go

@@ -89,7 +89,7 @@ func UnmarshalStrict(in []byte, out interface{}) (err error) {
 	return unmarshal(in, out, true)
 }
 
-// A Decorder reads and decodes YAML values from an input stream.
+// A Decoder reads and decodes YAML values from an input stream.
 type Decoder struct {
 	strict bool
 	parser *parser

vendor/gopkg.in/yaml.v2/yamlh.go

@@ -579,6 +579,7 @@ type yaml_parser_t struct {
 
 	simple_key_allowed bool                // May a simple key occur at the current position?
 	simple_keys        []yaml_simple_key_t // The stack of simple keys.
+	simple_keys_by_tok map[int]int         // possible simple_key indexes indexed by token_number
 
 	// Parser stuff