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

Message-Id: <DATYE858ERJP.9B9NY8NPMOM2@kernel.org>
Date: Mon, 23 Jun 2025 15:40:05 +0200
From: "Benno Lossin" <lossin@...nel.org>
To: "Danilo Krummrich" <dakr@...nel.org>, "Alice Ryhl"
 <aliceryhl@...gle.com>
Cc: <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 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...

---
Cheers,
Benno