linux-kernel - Re: [PATCH v2 4/4] rust: devres: implement register

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <aFlbe5zxPsxwl3zn@cassiopeiae>
Date: Mon, 23 Jun 2025 15:49:47 +0200
From: Danilo Krummrich <dakr@...nel.org>
To: Benno Lossin <lossin@...nel.org>
Cc: Alice Ryhl <aliceryhl@...gle.com>, gregkh@...uxfoundation.org,
	rafael@...nel.org, ojeda@...nel.org, alex.gaynor@...il.com,
	boqun.feng@...il.com, gary@...yguo.net, bjorn3_gh@...tonmail.com,
	a.hindborg@...nel.org, tmgross@...ch.edu, david.m.ertman@...el.com,
	ira.weiny@...el.com, leon@...nel.org, kwilczynski@...nel.org,
	bhelgaas@...gle.com, rust-for-linux@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH v2 4/4] rust: devres: implement register_release()

On Mon, Jun 23, 2025 at 03:40:05PM +0200, Benno Lossin wrote:
> On Mon Jun 23, 2025 at 2:51 PM CEST, Danilo Krummrich wrote:
> > On Mon, Jun 23, 2025 at 12:01:14PM +0000, Alice Ryhl wrote:
> >> On Sun, Jun 22, 2025 at 06:40:41PM +0200, Danilo Krummrich wrote:
> >> > +pub fn register_release<P>(dev: &Device<Bound>, data: P) -> Result
> >> > +where
> >> > +    P: ForeignOwnable,
> >> > +    for<'a> P::Borrowed<'a>: Release,
> >> 
> >> I think we need where P: ForeignOwnable + 'static too.
> >> 
> >> otherwise I can pass something with a reference that expires before the
> >> device is unbound and access it in the devm callback as a UAF.
> >
> > I can't really come up with an example for such a case, mind providing one? :)
> 
>     {
>         let local = MyLocalData { /* ... */ };
>         let data = Arc::new(Data { r: &local });
>         devres::register_release(dev, data)?;
>     }
>     // devres still holds onto `data`, but that points at `MyLocalData`
>     // which is on the stack and freed here...

Thanks for providing the example, I think I slightly misunderstood. Gonna add
the corresponding lifetime bound.