SessionMutationAfterClose

warning native on by default

Group: Probable bugs

Detect a write to $_SESSION after successful session_write_close and before a proven session_start reopening.

Example

<?php
session_start(); session_write_close(); $_SESSION['visits']++;

Reported:

• line 2: Persist session changes before closing the session.

Detection

• Report a write to $_SESSION after successful session_write_close and before a proven session_start reopening.
• Resolve builtin calls and named arguments before checking the contract. Project-local callees are considered only when their bodies or immutable summaries establish the required facts. The default is enabled, with positive proof required.
• For flow-dependent conditions, require a reachable source-to-use path with no intervening invalidation. Unknown calls, ambiguous aliases, recursion or analysis-budget exhaustion cannot establish definite facts.

Exceptions (no report)

• Reads, reopened sessions, failed close, externally persisted session wrappers and unknown session state are excluded.
• Unresolved targets, incomplete required facts, suppressed findings and PHP versions lacking the referenced API or language feature produce no report. User declarations shadowing builtin names are not builtin contracts.

Fix

No automatic fix: moving writes or reopening a session changes locking and failure behavior.

PHP versions

Apply only on PHP versions supporting the referenced APIs and syntax (within PHP 5.3–8.5). Builtin behavior and argument contracts follow the configured PHP version. Extension-specific calls require resolved extension API symbols; do not treat same-named application functions as extension calls.

Options

None. Enable or disable this rule through normal rule configuration.

Configure

In custos.json:

{
  "rules": {
    "SessionMutationAfterClose": {
      "enabled": false
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file):

// @custos-ignore SessionMutationAfterClose