From 0c71f9385d92016e96e1b226f91b3d14282fbd14 Mon Sep 17 00:00:00 2001
From: Christian Haudum <christian.haudum@gmail.com>
Date: Fri, 4 Oct 2024 17:10:50 +0200
Subject: [PATCH] fix(logql): Fix panic in json parsing when using invalid
 array index

This PR fixes a panic that occurs with the following json parser
expression:

```
| json keys[""]
```

when the log line is the following:

```json
{"keys": ["a", "b", "c"]}
```

Signed-off-by: Christian Haudum <christian.haudum@gmail.com>
---
 pkg/logql/log/parser_test.go                  | 20 +++++++++++++++++++
 .../github.com/grafana/jsonparser/parser.go   |  6 +-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/pkg/logql/log/parser_test.go b/pkg/logql/log/parser_test.go
index 28989b7cb5fe..fd08467af858 100644
--- a/pkg/logql/log/parser_test.go
+++ b/pkg/logql/log/parser_test.go
@@ -368,6 +368,26 @@ func TestJSONExpressionParser(t *testing.T) {
 			labels.FromStrings("param", "1"),
 			NoParserHints(),
 		},
+		{
+			"object element not present",
+			testLine,
+			[]LabelExtractionExpr{
+				NewLabelExtractionExpr("undefined", `pod[""]`),
+			},
+			labels.EmptyLabels(),
+			labels.FromStrings("undefined", ""),
+			NoParserHints(),
+		},
+		{
+			"accessing invalid array index",
+			testLine,
+			[]LabelExtractionExpr{
+				NewLabelExtractionExpr("param", `pod.deployment.params[""]`),
+			},
+			labels.EmptyLabels(),
+			labels.FromStrings("param", ""),
+			NoParserHints(),
+		},
 		{
 			"array string element",
 			testLine,
diff --git a/vendor/github.com/grafana/jsonparser/parser.go b/vendor/github.com/grafana/jsonparser/parser.go
index 5df2a463dcee..df49f2aba0f2 100644
--- a/vendor/github.com/grafana/jsonparser/parser.go
+++ b/vendor/github.com/grafana/jsonparser/parser.go
@@ -512,7 +512,7 @@ func EachKey(data []byte, cb func(int, []byte, ValueType, error), paths ...[]str
 			}
 
 			for pi, p := range paths {
-				if len(p) < level+1 || pathFlags[pi] || p[level][0] != '[' || !sameTree(p, pathsBuf[:level]) {
+				if len(p) < level+1 || pathFlags[pi] || p[level] == "" || p[level][0] != '[' || !sameTree(p, pathsBuf[:level]) {
 					continue
 				}
 				if len(p[level]) >= 2 {
@@ -712,12 +712,10 @@ func WriteToBuffer(buffer []byte, str string) int {
 }
 
 /*
-
 Del - Receives existing data structure, path to delete.
 
 Returns:
 `data` - return modified data
-
 */
 func Delete(data []byte, keys ...string) []byte {
 	lk := len(keys)
@@ -798,13 +796,11 @@ func Delete(data []byte, keys ...string) []byte {
 }
 
 /*
-
 Set - Receives existing data structure, path to set, and data to set at that key.
 
 Returns:
 `value` - modified byte array
 `err` - On any parsing error
-
 */
 func Set(data []byte, setValue []byte, keys ...string) (value []byte, err error) {
 	// ensure keys are set