From db359f50d44c2440fde15215f8dd46ec0eacc559 Mon Sep 17 00:00:00 2001
From: Kousuke Saruta <sarutak@apache.org>
Date: Fri, 4 Aug 2023 16:33:21 +0900
Subject: [PATCH] Fix to deny invalid field names. (#2414)

---
 lang/rust/avro/src/error.rs  |  3 +++
 lang/rust/avro/src/schema.rs | 38 ++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/lang/rust/avro/src/error.rs b/lang/rust/avro/src/error.rs
index 908dab7704d..97c929ad780 100644
--- a/lang/rust/avro/src/error.rs
+++ b/lang/rust/avro/src/error.rs
@@ -307,6 +307,9 @@ pub enum Error {
     #[error("Invalid enum symbol name {0}")]
     EnumSymbolName(String),
 
+    #[error("Invalid field name {0}")]
+    FieldName(String),
+
     #[error("Invalid schema name {0}. It must match the regex '{1}'")]
     InvalidSchemaName(String, &'static str),
 
diff --git a/lang/rust/avro/src/schema.rs b/lang/rust/avro/src/schema.rs
index 9ab6ce7ec41..6185bb67201 100644
--- a/lang/rust/avro/src/schema.rs
+++ b/lang/rust/avro/src/schema.rs
@@ -43,6 +43,8 @@ lazy_static! {
     // An optional namespace (with optional dots) followed by a name without any dots in it.
     static ref SCHEMA_NAME_R: Regex =
         Regex::new(r"^((?P<namespace>[A-Za-z_][A-Za-z0-9_\.]*)*\.)?(?P<name>[A-Za-z_][A-Za-z0-9_]*)$").unwrap();
+
+    static ref FIELD_NAME_R: Regex = Regex::new(r"^[A-Za-z_][A-Za-z0-9_]*$").unwrap();
 }
 
 /// Represents an Avro schema fingerprint
@@ -622,6 +624,10 @@ impl RecordField {
     ) -> AvroResult<Self> {
         let name = field.name().ok_or(Error::GetNameFieldFromRecord)?;
 
+        if !FIELD_NAME_R.is_match(&name) {
+            return Err(Error::FieldName(name));
+        }
+
         // TODO: "type" = "<record name>"
         let schema = parser.parse_complex(field, enclosing_namespace)?;
 
@@ -5026,4 +5032,36 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn test_avro_3820_deny_invalid_field_names() -> TestResult {
+        let schema_str = r#"
+        {
+          "name": "my_record",
+          "type": "record",
+          "fields": [
+            {
+              "name": "f1.x",
+              "type": {
+                "name": "my_enum",
+                "type": "enum",
+                "symbols": ["a"]
+              }
+            },  {
+              "name": "f2",
+              "type": {
+                "name": "my_fixed",
+                "type": "fixed",
+                "size": 1
+              }
+            }
+          ]
+        }
+        "#;
+
+        match Schema::parse_str(schema_str) {
+            Err(Error::FieldName(x)) if x == "f1.x" => Ok(()),
+            other => Err(format!("Expected Error::FieldName, got {other:?}").into()),
+        }
+    }
 }