From 089524c31ac8098965f9ed69d89a5de127b4bbbb Mon Sep 17 00:00:00 2001 From: Paul Dicker Date: Wed, 6 Feb 2019 14:20:27 +0100 Subject: [PATCH] Correct OpenOptions::security_qos_flags documentation --- src/libstd/sys/windows/ext/fs.rs | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/src/libstd/sys/windows/ext/fs.rs b/src/libstd/sys/windows/ext/fs.rs index 89038da6295..85967516933 100644 --- a/src/libstd/sys/windows/ext/fs.rs +++ b/src/libstd/sys/windows/ext/fs.rs @@ -220,13 +220,27 @@ pub trait OpenOptionsExt { /// the specified value (or combines it with `custom_flags` and `attributes` /// to set the `dwFlagsAndAttributes` for [`CreateFile`]). /// - /// By default, `security_qos_flags` is set to `SECURITY_ANONYMOUS`. For - /// information about possible values, see [Impersonation Levels] on the - /// Windows Dev Center site. + /// By default `security_qos_flags` is not set. It should be specified when + /// opening a named pipe, to control to which degree a server process can + /// act on behalf of a client process (security impersonation level). /// + /// When `security_qos_flags` is not set a malicious program can gain the + /// elevated privileges of a privileged Rust process when it allows opening + /// user-specified paths, by tricking it into opening a named pipe. So + /// arguably `security_qos_flags` should also be set when opening arbitrary + /// paths. However the bits can then conflict with other flags, specifically + /// `FILE_FLAG_OPEN_NO_RECALL`. + /// + /// For information about possible values, see [Impersonation Levels] on the + /// Windows Dev Center site. The `SECURITY_SQOS_PRESENT` flag is set + /// automatically when using this method. + /// # Examples /// /// ```no_run + /// # #[cfg(for_demonstration_only)] + /// extern crate winapi; + /// # mod winapi { pub const SECURITY_IDENTIFICATION: u32 = 0; } /// use std::fs::OpenOptions; /// use std::os::windows::prelude::*; /// @@ -235,9 +249,9 @@ pub trait OpenOptionsExt { /// .create(true) /// /// // Sets the flag value to `SecurityIdentification`. - /// .security_qos_flags(1) + /// .security_qos_flags(winapi::SECURITY_IDENTIFICATION) /// - /// .open("foo.txt"); + /// .open(r"\\.\pipe\MyPipe"); /// ``` /// /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx