From 2eef4f966f9df2fd673433ddc8a69535d7e99115 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8F=8D=E6=83=9C?= <ienfreeireland@gmail.com>
Date: Fri, 25 Sep 2026 08:37:33 -0700
Subject: [PATCH] Reject partial or overflowing user ids (#168)

Co-authored-by: HttpAnimations <shawndouglasyt@gmail.com>
---
 src/jnivm/jnivm.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/jnivm/jnivm.cc b/src/jnivm/jnivm.cc
index d9fd7e2..ca54648 100644
--- a/src/jnivm/jnivm.cc
+++ b/src/jnivm/jnivm.cc
@@ -1581,9 +1581,13 @@ jlong ParseLocalStorageUserIdFromEnv() {
   if (!value || value[0] == '\0') {
     return 0;
   }
+  errno = 0;
   char* end = nullptr;
   long long parsed = std::strtoll(value, &end, 10);
-  return end == value ? 0 : static_cast<jlong>(parsed);
+  if (errno == ERANGE || end == value || *end != '\0') {
+    return 0;
+  }
+  return static_cast<jlong>(parsed);
 }
 
 jlong CurrentLocalStorageUserLocked() {