Double Free in Adonisjs with Cockroachdb

A Double Free vulnerability occurs when a program attempts to free the same block of memory more than once. In the context of AdonisJS interacting with CockroachDB, this typically arises through improper management of query result objects, connection pools, or ORM model instances rather than in the database engine itself. CockroachDB, as a distributed SQL database, does not introduce Double Free directly; however, the way AdonisJS handles database responses, transactions, and client connections can create conditions where underlying resources are released multiple times due to application logic errors.

When using AdonisJS with CockroachDB, developers often rely on the ORM or raw query clients to manage database interactions. If a developer manually manages database clients or result sets—such as closing a connection pool entry and then later attempting to release it again—this can map to a Double Free pattern at the system or library level. For example, improperly handling a transaction object or reusing a query builder instance after it has been explicitly destroyed can lead to the runtime attempting to free the same memory or connection handle twice. This is especially risky when using asynchronous patterns where multiple callbacks or promise chains reference the same object.

Another exposure path involves improper error handling around connection acquisition and release. AdonisJS applications may request a client from a connection pool to execute a CockroachDB query. If an error occurs and the client is released in an error handler, but the normal flow also attempts to release the same client, the underlying system resources can be double freed. This does not corrupt the CockroachDB data on disk, but it can destabilize the application process, leading to crashes or undefined behavior. The risk is heightened when developers use low-level database clients directly instead of leveraging AdonisJS’s managed abstractions.

Consider a scenario where a developer uses the Database manager to run raw queries against CockroachDB and then manually closes connections in both success and error paths without tracking state:

const Database = use('Database')

async function unsafeQuery() {
  let client
  try {
    client = await Database.connection()
    const result = await client.query('SELECT * FROM users WHERE id = $1', [userId])
    return result.rows
  } catch (error) {
    if (client) await client.release()
    throw error
  } finally {
    if (client) await client.release()
  }
}

In this pattern, if no error occurs, the finally block releases the client. If an error occurs before the try block completes, the catch block also releases the client. This results in a double release, which under the hood can map to a Double Free condition within the client or pool implementation. While AdonisJS provides higher-level APIs that handle this automatically, bypassing them increases risk.

LLM/AI Security considerations are relevant when scanning API endpoints that expose database interaction logic. An endpoint that reflects database internals or stack traces might inadvertently reveal patterns that suggest resource mismanagement. middleBrick’s LLM/AI Security checks can detect such risky code patterns by analyzing system prompts and outputs for indicators of unsafe resource handling, helping developers identify insecure API designs before deployment.

To prevent Double Free conditions when using AdonisJS with CockroachDB, ensure that database clients are released exactly once and that all code paths avoid redundant release calls. The safest approach is to rely on AdonisJS’s built-in connection management and avoid manual client handling wherever possible. When manual handling is necessary, use state flags or structured patterns to guarantee single release.

Use AdonisJS’s Database transaction helper, which automatically manages client acquisition and release:

const Database = use('Database')

async function safeTransaction() {
  return await Database.transaction(async (client) => {
    const result = await client.query('SELECT * FROM accounts WHERE id = $1', [accountId])
    // Perform operations using the client
    return result.rows
  })
}

The transaction helper ensures the client is released exactly once when the callback completes, regardless of success or error, eliminating the double release risk.

For raw queries where transactions are not needed, use a try/finally pattern with a released guard:

const Database = use('Database')

async function safeQuery() {
  const client = await Database.connection()
  try {
    const result = await client.query('SELECT * FROM products WHERE category = $1', ['books'])
    return result.rows
  } finally {
    if (client._released !== true) {
      await client.release()
      client._released = true
    }
  }
}

This pattern ensures the client is released only once by tracking release state. The _released guard prevents double free even if finally and error handling both attempt release.

When using connection pools directly, configure pool limits appropriately and ensure that middleware or hooks do not trigger multiple releases. For example, in a custom provider, manage client lifecycle carefully:

const { Client } = require('@adonisjs/lucid')
const db = new Client({
  connection: 'cockroachdb',
  debug: false
})

async function runWithPool() {
  const client = await db.connect()
  try {
    const rows = await client.from('orders').where('status', 'shipped').select('*')
    return rows
  } finally {
    if (client._pool?.release && !client._released) {
      client._pool.release(client)
      client._released = true
    }
  }
}

These examples demonstrate CockroachDB-specific remediation by focusing on correct client lifecycle management within AdonisJS. By using built-in transaction helpers, adding release guards, and avoiding manual double-release logic, developers can mitigate Double Free risks. middleBrick’s CLI tool can be used to scan for risky patterns in codebases, and the GitHub Action can enforce security thresholds in CI/CD pipelines to catch such issues before deployment.