From 64406c5996a0775493c8a2acd457e612bd84cde6 Mon Sep 17 00:00:00 2001 From: Tomoaki Kawada Date: Thu, 10 Feb 2022 13:10:25 +0900 Subject: [PATCH] kmc-solid: Use the filesystem thread-safety wrapper Neither the SOLID filesystem API nor built-in filesystems guarantee thread safety by default. Although this may suffice in general embedded- system use cases, and in fact the API can be used from multiple threads without any problems in many cases, this has been a source of unsoundness in `std::sys::solid::fs`. This commit updates the `std` code to leverage the filesystem thread- safety wrapper to enforce thread safety. This is done by prefixing all paths passed to the filesystem API with `\TS`. (Note that relative paths aren't supported in this platform.) --- library/std/src/sys/solid/fs.rs | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/library/std/src/sys/solid/fs.rs b/library/std/src/sys/solid/fs.rs index a6ed10f7789d2..a2cbee4dcf07b 100644 --- a/library/std/src/sys/solid/fs.rs +++ b/library/std/src/sys/solid/fs.rs @@ -289,7 +289,26 @@ impl OpenOptions { } fn cstr(path: &Path) -> io::Result { - Ok(CString::new(path.as_os_str().as_bytes())?) + let path = path.as_os_str().as_bytes(); + + if !path.starts_with(br"\") { + // Relative paths aren't supported + return Err(crate::io::const_io_error!( + crate::io::ErrorKind::Unsupported, + "relative path is not supported on this platform", + )); + } + + // Apply the thread-safety wrapper + const SAFE_PREFIX: &[u8] = br"\TS"; + let wrapped_path = [SAFE_PREFIX, &path, &[0]].concat(); + + CString::from_vec_with_nul(wrapped_path).map_err(|_| { + crate::io::const_io_error!( + io::ErrorKind::InvalidInput, + "path provided contains a nul byte", + ) + }) } impl File {