| Message ID | 20241004-rust-lockdep-v1-1-e9a5c45721fc@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | rust: lockdep: Fix soundness issue affecting LockClassKeys | expand |
Am 05.10.24 um 00:01 schrieb Mitchell Levy via B4 Relay: > From: Mitchell Levy <levymitchell0@gmail.com> > > Currently, dynamically allocated LockCLassKeys can be used from the Rust > side without having them registered. This is a soundness issue, so > remove them. > > Suggested-by: Alice Ryhl <aliceryhl@google.com> > Link: https://lore.kernel.org/rust-for-linux/20240815074519.2684107-3-nmi@metaspace.dk/ > Cc: stable@vger.kernel.org > Signed-off-by: Mitchell Levy <levymitchell0@gmail.com> > --- > rust/kernel/lib.rs | 2 +- > rust/kernel/sync.rs | 14 ++------------ > 2 files changed, 3 insertions(+), 13 deletions(-) > > diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs > index 22a3bfa5a9e9..b5f4b3ce6b48 100644 > --- a/rust/kernel/lib.rs > +++ b/rust/kernel/lib.rs > @@ -44,8 +44,8 @@ > pub mod page; > pub mod prelude; > pub mod print; > -pub mod sizes; > pub mod rbtree; > +pub mod sizes; > mod static_assert; > #[doc(hidden)] > pub mod std_vendor; This is fixed already https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/rust/kernel/lib.rs?id=ece207a83e464af710d641f29e32b7a144c48e79 and can be dropped here. > diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs > index 0ab20975a3b5..d270db9b9894 100644 > --- a/rust/kernel/sync.rs > +++ b/rust/kernel/sync.rs > @@ -27,28 +27,18 @@ > 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(); Should the SAFETY comment added in the 2nd patch go to here? + // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated + // lock_class_key > + static CLASS: $crate::sync::LockClassKey = > + unsafe { ::core::mem::MaybeUninit::uninit().assume_init() }; > &CLASS > }}; > } >
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 22a3bfa5a9e9..b5f4b3ce6b48 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -44,8 +44,8 @@ pub mod page; pub mod prelude; pub mod print; -pub mod sizes; pub mod rbtree; +pub mod sizes; mod static_assert; #[doc(hidden)] pub mod std_vendor; diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 0ab20975a3b5..d270db9b9894 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -27,28 +27,18 @@ 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 = + unsafe { ::core::mem::MaybeUninit::uninit().assume_init() }; &CLASS }}; }