From 1649138a291e697faafe4f4c3b4a05a603d0c0cb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stanis=C5=82aw=20Wi=C5=9Bniewski?=
 <s.wisniewski1101@gmail.com>
Date: Sat, 15 Apr 2023 08:09:22 +0200
Subject: [PATCH] LibC: Return nullptr if allocation fails in strdup() and
 strndup()

If allocation would fail, we would continue to UB at memcpy
and nullptr dereference before returning.
---
 Userland/Libraries/LibC/string.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Userland/Libraries/LibC/string.cpp b/Userland/Libraries/LibC/string.cpp
index 28fb2ce34f..7e31d1f053 100644
--- a/Userland/Libraries/LibC/string.cpp
+++ b/Userland/Libraries/LibC/string.cpp
@@ -72,6 +72,8 @@ char* strdup(char const* str)
 {
     size_t len = strlen(str);
     char* new_str = (char*)malloc(len + 1);
+    if (!new_str)
+        return nullptr;
     memcpy(new_str, str, len);
     new_str[len] = '\0';
     return new_str;
@@ -82,6 +84,8 @@ char* strndup(char const* str, size_t maxlen)
 {
     size_t len = strnlen(str, maxlen);
     char* new_str = (char*)malloc(len + 1);
+    if (!new_str)
+        return nullptr;
     memcpy(new_str, str, len);
     new_str[len] = 0;
     return new_str;