bianbu-linux-6.6/rust/kernel
Laine Taffin Altman c34a8052af rust: init: remove impl Zeroable for Infallible
commit 49ceae68a0df9a92617a61e9ce8a0efcf6419585 upstream.

In Rust, producing an invalid value of any type is immediate undefined
behavior (UB); this includes via zeroing memory.  Therefore, since an
uninhabited type has no valid values, producing any values at all for it is
UB.

The Rust standard library type `core::convert::Infallible` is uninhabited,
by virtue of having been declared as an enum with no cases, which always
produces uninhabited types in Rust.

The current kernel code allows this UB to be triggered, for example by code
like `Box::<core::convert::Infallible>::init(kernel::init::zeroed())`.

Thus, remove the implementation of `Zeroable` for `Infallible`, thereby
avoiding the unsoundness (potential for future UB).

Cc: stable@vger.kernel.org
Fixes: 38cde0bd7b ("rust: init: add `Zeroable` trait and `init::zeroed` function")
Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13
Signed-off-by: Laine Taffin Altman <alexanderaltman@me.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/CA160A4E-561E-4918-837E-3DCEBA74F808@me.com
[ Reformatted the comment slightly. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-02 16:32:42 +02:00
..
init rust: init: update expanded macro explanation 2023-08-21 14:31:49 +02:00
sync rust: arc: add explicit drop() around Box::from_raw() 2024-02-16 19:10:43 +01:00
allocator.rs rust: upgrade to Rust 1.71.1 2023-08-14 17:50:02 +02:00
build_assert.rs rust: upgrade to Rust 1.68.2 2023-05-31 17:35:03 +02:00
error.rs rust: error: Markdown style nit 2023-10-12 22:58:52 +02:00
init.rs rust: init: remove impl Zeroable for Infallible 2024-05-02 16:32:42 +02:00
ioctl.rs rust: ioctl: Add ioctl number manipulation functions 2023-04-22 01:46:45 +02:00
kunit.rs rust: support running Rust documentation tests as KUnit ones 2023-07-19 09:32:53 -06:00
lib.rs Rust changes for v6.6 2023-08-29 08:19:46 -07:00
prelude.rs rust: add derive macro for Zeroable 2023-08-21 14:31:48 +02:00
print.rs rust: print: use explicit link in documentation 2024-02-16 19:10:43 +01:00
static_assert.rs rust: static_assert: add static_assert! macro 2022-12-04 01:59:16 +01:00
std_vendor.rs rust: upgrade to Rust 1.68.2 2023-05-31 17:35:03 +02:00
str.rs rust: str: make doctests compilable/testable 2023-07-19 09:25:02 -06:00
sync.rs rust: sync: introduce CondVar 2023-04-22 01:46:45 +02:00
task.rs rust: task: remove redundant explicit link 2024-02-16 19:10:43 +01:00
types.rs Rust changes for v6.6 2023-08-29 08:19:46 -07:00