fix: Strip breadcrumb metadata on OOM to prevent silent event loss

src/Integration/FatalErrorListenerIntegration.php

@@ -4,9 +4,11 @@
 
 namespace Sentry\Integration;
 
+use Sentry\Breadcrumb;
 use Sentry\ErrorHandler;
 use Sentry\Exception\FatalErrorException;
 use Sentry\SentrySdk;
+use Sentry\State\Scope;
 
 /**
  * This integration hooks into the error handler and captures fatal errors.
@@ -15,6 +17,12 @@
  */
 final class FatalErrorListenerIntegration extends AbstractErrorListenerIntegration
 {
+    /**
+     * Intentionally looser than ErrorHandler::OOM_MESSAGE_MATCHER — matches the
+     * prefixed FatalErrorException message and needs no capture groups.
+     */
+    private const OOM_MESSAGE_MATCHER = '/Allowed memory size of \d+ bytes exhausted/';
+
     /**
      * {@inheritdoc}
      */
@@ -36,6 +44,27 @@ public function setupOnce(): void
                 return;
             }
 
+            if (preg_match(self::OOM_MESSAGE_MATCHER, $exception->getMessage()) === 1) {
+                $currentHub->configureScope(static function (Scope $scope): void {
+                    $strippedBreadcrumbs = array_map(static function (Breadcrumb $breadcrumb): Breadcrumb {
+                        return new Breadcrumb(
+                            $breadcrumb->getLevel(),
+                            $breadcrumb->getType(),
+                            $breadcrumb->getCategory(),
+                            $breadcrumb->getMessage(),
+                            [],
+                            $breadcrumb->getTimestamp()
+                        );
+                    }, $scope->getBreadcrumbs());
+
+                    $scope->clearBreadcrumbs();
+
+                    foreach ($strippedBreadcrumbs as $breadcrumb) {
+                        $scope->addBreadcrumb($breadcrumb, \count($strippedBreadcrumbs));
+                    }
+                });
+            }
+
             $integration->captureException($currentHub, $exception);
         });
     }

src/State/Scope.php

@@ -326,6 +326,16 @@ public function addBreadcrumb(Breadcrumb $breadcrumb, int $maxBreadcrumbs = 100)
         return $this;
     }
 
+    /**
+     * Gets the breadcrumbs.
+     *
+     * @return Breadcrumb[]
+     */
+    public function getBreadcrumbs(): array
+    {
+        return $this->breadcrumbs;
+    }
+
     /**
      * Clears all the breadcrumbs.
      *

tests/phpt-oom/php84/out_of_memory_fatal_error_increases_memory_limit.phpt

@@ -2,7 +2,7 @@
 Test that when handling a out of memory error the memory limit is increased with 5 MiB and the event is serialized and ready to be sent
 --SKIPIF--
 <?php
-if (PHP_VERSION_ID >= 80400) {
+if (PHP_VERSION_ID >= 80500) {
     die('skip - only works for PHP 8.4 and below');
 }
 --INI--
@@ -24,6 +24,8 @@ use Sentry\Transport\Result;
 use Sentry\Transport\ResultStatus;
 use Sentry\Transport\TransportInterface;
 
+error_reporting(E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED);
+
 $vendor = __DIR__;
 
 while (!file_exists($vendor . '/vendor')) {
@@ -32,8 +34,6 @@ while (!file_exists($vendor . '/vendor')) {
 
 require $vendor . '/vendor/autoload.php';
 
-error_reporting(E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED);
-
 $options = new Options([
     'dsn' => 'http://public@example.com/sentry/1',
 ]);

tests/phpt-oom/php84/out_of_memory_with_large_breadcrumbs_strips_metadata.phpt

@@ -0,0 +1,104 @@
+--TEST--
+Test that when handling an OOM error with large breadcrumbs, breadcrumb metadata is stripped to prevent secondary OOM during serialization
+--SKIPIF--
+<?php
+if (PHP_VERSION_ID >= 80500) {
+    die('skip - only works for PHP 8.4 and below');
+}
+--INI--
+memory_limit=67108864
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+namespace Sentry\Tests;
+
+use Sentry\Breadcrumb;
+use Sentry\ClientBuilder;
+use Sentry\Event;
+use Sentry\Options;
+use Sentry\SentrySdk;
+use Sentry\Serializer\PayloadSerializer;
+use Sentry\Serializer\PayloadSerializerInterface;
+use Sentry\Transport\Result;
+use Sentry\Transport\ResultStatus;
+use Sentry\Transport\TransportInterface;
+
+error_reporting(E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED);
+
+$vendor = __DIR__;
+
+while (!file_exists($vendor . '/vendor')) {
+    $vendor = \dirname($vendor);
+}
+
+require $vendor . '/vendor/autoload.php';
+
+$options = new Options([
+    'dsn' => 'http://public@example.com/sentry/1',
+]);
+
+$transport = new class(new PayloadSerializer($options)) implements TransportInterface {
+    private $payloadSerializer;
+
+    public function __construct(PayloadSerializerInterface $payloadSerializer)
+    {
+        $this->payloadSerializer = $payloadSerializer;
+    }
+
+    public function send(Event $event): Result
+    {
+        $breadcrumbs = $event->getBreadcrumbs();
+        echo 'Breadcrumb count: ' . \count($breadcrumbs) . \PHP_EOL;
+
+        if (\count($breadcrumbs) > 0) {
+            $firstBreadcrumb = $breadcrumbs[0];
+            echo 'First breadcrumb category: ' . $firstBreadcrumb->getCategory() . \PHP_EOL;
+            echo 'First breadcrumb has metadata: ' . (empty($firstBreadcrumb->getMetadata()) ? 'no' : 'yes') . \PHP_EOL;
+        }
+
+        $this->payloadSerializer->serialize($event);
+
+        echo 'Transport called' . \PHP_EOL;
+
+        return new Result(ResultStatus::success());
+    }
+
+    public function close(?int $timeout = null): Result
+    {
+        return new Result(ResultStatus::success());
+    }
+};
+
+$options->setTransport($transport);
+
+$client = (new ClientBuilder($options))->getClient();
+
+SentrySdk::init()->bindClient($client);
+
+// Add 100 breadcrumbs with ~100KB metadata each to simulate the real-world scenario
+$hub = SentrySdk::getCurrentHub();
+$hub->configureScope(function (\Sentry\State\Scope $scope): void {
+    for ($i = 0; $i < 100; ++$i) {
+        $scope->addBreadcrumb(new Breadcrumb(
+            Breadcrumb::LEVEL_INFO,
+            Breadcrumb::TYPE_DEFAULT,
+            'db.query',
+            'SELECT * FROM large_table WHERE id = ?',
+            ['bindings' => str_repeat('x', 100 * 1024)]
+        ));
+    }
+});
+
+// Trigger OOM - the remaining memory after breadcrumbs is limited
+$array = [];
+for ($i = 0; $i < 100000000; ++$i) {
+    $array[] = 'sentry';
+}
+--EXPECTF--
+Fatal error: Allowed memory size of %d bytes exhausted (tried to allocate %d bytes) in %s on line %d
+Breadcrumb count: 100
+First breadcrumb category: db.query
+First breadcrumb has metadata: no
+Transport called

tests/phpt-oom/php85/out_of_memory_with_large_breadcrumbs_strips_metadata.phpt

@@ -0,0 +1,106 @@
+--TEST--
+Test that when handling an OOM error with large breadcrumbs, breadcrumb metadata is stripped to prevent secondary OOM during serialization
+--SKIPIF--
+<?php
+if (PHP_VERSION_ID < 80500) {
+    die('skip - only works for PHP 8.5 and above');
+}
+--INI--
+memory_limit=67108864
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+namespace Sentry\Tests;
+
+use Sentry\Breadcrumb;
+use Sentry\ClientBuilder;
+use Sentry\Event;
+use Sentry\Options;
+use Sentry\SentrySdk;
+use Sentry\Serializer\PayloadSerializer;
+use Sentry\Serializer\PayloadSerializerInterface;
+use Sentry\Transport\Result;
+use Sentry\Transport\ResultStatus;
+use Sentry\Transport\TransportInterface;
+
+error_reporting(E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED);
+
+$vendor = __DIR__;
+
+while (!file_exists($vendor . '/vendor')) {
+    $vendor = \dirname($vendor);
+}
+
+require $vendor . '/vendor/autoload.php';
+
+$options = new Options([
+    'dsn' => 'http://public@example.com/sentry/1',
+]);
+
+$transport = new class(new PayloadSerializer($options)) implements TransportInterface {
+    private $payloadSerializer;
+
+    public function __construct(PayloadSerializerInterface $payloadSerializer)
+    {
+        $this->payloadSerializer = $payloadSerializer;
+    }
+
+    public function send(Event $event): Result
+    {
+        $breadcrumbs = $event->getBreadcrumbs();
+        echo 'Breadcrumb count: ' . \count($breadcrumbs) . \PHP_EOL;
+
+        if (\count($breadcrumbs) > 0) {
+            $firstBreadcrumb = $breadcrumbs[0];
+            echo 'First breadcrumb category: ' . $firstBreadcrumb->getCategory() . \PHP_EOL;
+            echo 'First breadcrumb has metadata: ' . (empty($firstBreadcrumb->getMetadata()) ? 'no' : 'yes') . \PHP_EOL;
+        }
+
+        $this->payloadSerializer->serialize($event);
+
+        echo 'Transport called' . \PHP_EOL;
+
+        return new Result(ResultStatus::success());
+    }
+
+    public function close(?int $timeout = null): Result
+    {
+        return new Result(ResultStatus::success());
+    }
+};
+
+$options->setTransport($transport);
+
+$client = (new ClientBuilder($options))->getClient();
+
+SentrySdk::init()->bindClient($client);
+
+// Add 100 breadcrumbs with ~100KB metadata each to simulate the real-world scenario
+$hub = SentrySdk::getCurrentHub();
+$hub->configureScope(function (\Sentry\State\Scope $scope): void {
+    for ($i = 0; $i < 100; ++$i) {
+        $scope->addBreadcrumb(new Breadcrumb(
+            Breadcrumb::LEVEL_INFO,
+            Breadcrumb::TYPE_DEFAULT,
+            'db.query',
+            'SELECT * FROM large_table WHERE id = ?',
+            ['bindings' => str_repeat('x', 100 * 1024)]
+        ));
+    }
+});
+
+// Trigger OOM - the remaining memory after breadcrumbs is limited
+$array = [];
+for ($i = 0; $i < 100000000; ++$i) {
+    $array[] = 'sentry';
+}
+--EXPECTF--
+Fatal error: Allowed memory size of %d bytes exhausted (tried to allocate %d bytes) in %s on line %d
+Stack trace:
+%A
+Breadcrumb count: 100
+First breadcrumb category: db.query
+First breadcrumb has metadata: no
+Transport called