linux-kernel - Re: [PATCH] rust: init: fix `Zeroable` implementation for `Option<NonNull<T>>` and `Option<KBox<T>>`

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: <D88DKEJ9LHA0.3324DAQAUEI9T@proton.me>
Date: Wed, 05 Mar 2025 13:42:55 +0000
From: Benno Lossin <benno.lossin@...ton.me>
To: Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor <alex.gaynor@...il.com>, Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>, Björn Roy Baron <bjorn3_gh@...tonmail.com>, Benno Lossin <benno.lossin@...ton.me>, Andreas Hindborg <a.hindborg@...nel.org>, Alice Ryhl <aliceryhl@...gle.com>, Trevor Gross <tmgross@...ch.edu>
Cc: stable@...r.kernel.org, rust-for-linux@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] rust: init: fix `Zeroable` implementation for `Option<NonNull<T>>` and `Option<KBox<T>>`

On Wed Mar 5, 2025 at 2:29 PM CET, Benno Lossin wrote:
> According to [1], `NonNull<T>` and `#[repr(transparent)]` wrapper types
> such as our custom `KBox<T>` have the null pointer optimization only if
> `T: Sized`. Thus remove the `Zeroable` implementation for the unsized
> case.
>
> Link: https://doc.rust-lang.org/stable/std/option/index.html#representation [1]
> Cc: stable@...r.kernel.org # v6.12+ (a custom patch will be needed for 6.6.y)
> Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function")
> Signed-off-by: Benno Lossin <benno.lossin@...ton.me>

Forgot to add this:

Reported-by: Alice Ryhl <aliceryhl@...gle.com>

---
Cheers,
Benno