6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mitchell Levy levymitchell0@gmail.com
commit 966944f3711665db13e214fef6d02982c49bb972 upstream.
Currently, dynamically allocated LockCLassKeys can be used from the Rust side without having them registered. This is a soundness issue, so remove them.
Fixes: 6ea5aa08857a ("rust: sync: introduce `LockClassKey`") Suggested-by: Alice Ryhl aliceryhl@google.com Signed-off-by: Mitchell Levy levymitchell0@gmail.com Signed-off-by: Boqun Feng boqun.feng@gmail.com Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Benno Lossin benno.lossin@proton.me Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250307232717.1759087-11-boqun.feng@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- rust/kernel/sync.rs | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-)
--- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -27,28 +27,20 @@ pub struct LockClassKey(Opaque<bindings: unsafe impl Sync for LockClassKey {}
impl LockClassKey { - /// Creates a new lock class key. - pub const fn new() -> Self { - Self(Opaque::uninit()) - } - pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { self.0.get() } }
-impl Default for LockClassKey { - fn default() -> Self { - Self::new() - } -} - /// Defines a new static lock class and returns a pointer to it. #[doc(hidden)] #[macro_export] macro_rules! static_lock_class { () => {{ - static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); + static CLASS: $crate::sync::LockClassKey = + // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated + // lock_class_key + unsafe { ::core::mem::MaybeUninit::uninit().assume_init() }; &CLASS }}; }