Issue #2642110 by beejeebus: Add recursion protection to LoggerChannell()

core/lib/Drupal/Core/Logger/LoggerChannel.php

@@ -19,6 +19,26 @@
 class LoggerChannel implements LoggerChannelInterface {
   use LoggerTrait;
 
+  /**
+   * Maximum call depth to self::log() for a single log message.
+   *
+   * It's very easy for logging channel code to call out to other library code
+   * that will create log messages. In that case, we will recurse back in to
+   * LoggerChannel::log() multiple times while processing a single originating
+   * message. To prevent infinite recursion, we track the call depth and bail
+   * out at LoggerChannel::MAX_CALL_DEPTH iterations.
+   *
+   * @var int
+   */
+  const MAX_CALL_DEPTH = 5;
+
+  /**
+   * Number of times LoggerChannel::log() has been called for a single message.
+   *
+   * @var int
+   */
+  protected $callDepth = 0;
+
   /**
    * The name of the channel of this logger instance.
    *
@@ -77,6 +97,11 @@ public function __construct($channel) {
    * {@inheritdoc}
    */
   public function log($level, $message, array $context = array()) {
+    if ($this->callDepth == self::MAX_CALL_DEPTH) {
+      return;
+    }
+    $this->callDepth++;
+
     // Merge in defaults.
     $context += array(
       'channel' => $this->channel,
@@ -115,6 +140,8 @@ public function log($level, $message, array $context = array()) {
     foreach ($this->sortLoggers() as $logger) {
       $logger->log($level, $message, $context);
     }
+
+    $this->callDepth--;
   }
 
   /**

core/tests/Drupal/Tests/Core/Logger/LoggerChannelTest.php

@@ -12,6 +12,8 @@
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\RequestStack;
+use Psr\Log\LoggerInterface;
+use Psr\Log\LoggerTrait;
 
 /**
  * @coversDefaultClass \Drupal\Core\Logger\LoggerChannel
@@ -54,6 +56,21 @@ public function testLog(callable $expected, Request $request = NULL, AccountInte
     $channel->log(rand(0, 7), $message);
   }
 
+  /**
+   * Tests LoggerChannel::log() recursion protection.
+   *
+   * @covers ::log
+   */
+  public function testLogRecursionProtection() {
+    $channel = new LoggerChannel('test');
+    $logger = $this->getMock('Psr\Log\LoggerInterface');
+    $logger->expects($this->exactly(LoggerChannel::MAX_CALL_DEPTH))
+      ->method('log');
+    $channel->addLogger($logger);
+    $channel->addLogger(new NaughtyRecursiveLogger($channel));
+    $channel->log(rand(0, 7), $this->randomMachineName());
+  }
+
   /**
    * Tests LoggerChannel::addLoggers().
    *
@@ -129,3 +146,19 @@ function ($context) {
   }
 
 }
+
+class NaughtyRecursiveLogger implements LoggerInterface  {
+  use LoggerTrait;
+
+  protected $channel;
+  protected $message;
+
+  public function __construct(LoggerChannel $channel) {
+    $this->channel = $channel;
+  }
+
+  public function log($level, $message, array $context = []) {
+    $this->channel->log(rand(0, 7), $message, $context);
+  }
+}
+