From 83db4b3f8124f0d1ff0d45872728359022c4c4b6 Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Fri, 22 Jul 2022 14:18:01 +0200
Subject: [PATCH] Handle depth to avoid cases where an exception has many too
 many previous exceptions, fixes #1726

---
 src/Monolog/Formatter/LineFormatter.php       | 6 ++++++
 src/Monolog/Formatter/NormalizerFormatter.php | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/src/Monolog/Formatter/LineFormatter.php b/src/Monolog/Formatter/LineFormatter.php
index d0b4de94..69dfee5c 100644
--- a/src/Monolog/Formatter/LineFormatter.php
+++ b/src/Monolog/Formatter/LineFormatter.php
@@ -153,6 +153,12 @@ class LineFormatter extends NormalizerFormatter
 
         if ($previous = $e->getPrevious()) {
             do {
+                $depth++;
+                if ($depth > $this->maxNormalizeDepth) {
+                    $str .= '\n[previous exception] Over ' . $this->maxNormalizeDepth . ' levels deep, aborting normalization';
+                    break;
+                }
+
                 $str .= "\n[previous exception] " . $this->formatException($previous);
             } while ($previous = $previous->getPrevious());
         }
diff --git a/src/Monolog/Formatter/NormalizerFormatter.php b/src/Monolog/Formatter/NormalizerFormatter.php
index 0c622715..5441bc0a 100644
--- a/src/Monolog/Formatter/NormalizerFormatter.php
+++ b/src/Monolog/Formatter/NormalizerFormatter.php
@@ -198,6 +198,10 @@ class NormalizerFormatter implements FormatterInterface
      */
     protected function normalizeException(Throwable $e, int $depth = 0)
     {
+        if ($depth > $this->maxNormalizeDepth) {
+            return ['Over ' . $this->maxNormalizeDepth . ' levels deep, aborting normalization'];
+        }
+
         if ($e instanceof \JsonSerializable) {
             return (array) $e->jsonSerialize();
         }