From ca9862578903a93089e6aae71bb8641b580bc4f6 Mon Sep 17 00:00:00 2001
From: Jonathan Marler <johnnymarler@gmail.com>
Date: Tue, 21 Jun 2022 03:21:45 -0600
Subject: [PATCH] std.os.execvpe: fix buffer overflow

The NameTooLong check isn't taking the sentinel 0 into account which
would result in a buffer overflow on the stack.
---
 lib/std/os.zig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/std/os.zig b/lib/std/os.zig
index c79bd6e7b0..578a8ddcbc 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -1821,11 +1821,11 @@ pub fn execvpeZ_expandArg0(
     };
 
     while (it.next()) |search_path| {
-        if (path_buf.len < search_path.len + file_slice.len + 1) return error.NameTooLong;
+        const path_len = search_path.len + file_slice.len + 1;
+        if (path_buf.len < path_len + 1) return error.NameTooLong;
         mem.copy(u8, &path_buf, search_path);
         path_buf[search_path.len] = '/';
         mem.copy(u8, path_buf[search_path.len + 1 ..], file_slice);
-        const path_len = search_path.len + file_slice.len + 1;
         path_buf[path_len] = 0;
         const full_path = path_buf[0..path_len :0].ptr;
         switch (arg0_expand) {