From 7ba2f7bc02cdbab9314f3804c698ec78e20c441e Mon Sep 17 00:00:00 2001
From: Sergiu Deitsch <sergiud@users.noreply.github.com>
Date: Thu, 5 Oct 2023 23:33:23 +0200
Subject: [PATCH] fix(demangle): prevent signed integer overflow (#955)

---
 src/demangle.cc | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/demangle.cc b/src/demangle.cc
index 3dde4a63e..1310c3b3f 100644
--- a/src/demangle.cc
+++ b/src/demangle.cc
@@ -37,6 +37,7 @@
 #include "demangle.h"
 
 #include <cstdio>  // for nullptr
+#include <limits>
 
 #include "utilities.h"
 
@@ -592,9 +593,23 @@ static bool ParseNumber(State *state, int *number_out) {
   }
   const char *p = state->mangled_cur;
   int number = 0;
+  constexpr int int_max_by_10 = std::numeric_limits<int>::max() / 10;
   for (;*p != '\0'; ++p) {
     if (IsDigit(*p)) {
-      number = number * 10 + (*p - '0');
+      // Prevent signed integer overflow when multiplying
+      if (number > int_max_by_10) {
+        return false;
+      }
+
+      const int digit = *p - '0';
+      const int shifted = number * 10;
+
+      // Prevent signed integer overflow when summing
+      if (digit > std::numeric_limits<int>::max() - shifted) {
+        return false;
+      }
+
+      number = shifted + digit;
     } else {
       break;
     }