bianbu-linux-6.6/rust
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
..
alloc rust: upgrade to Rust 1.73.0 2024-02-16 19:10:43 +01:00
bindings linux-kselftest-kunit-6.6-rc1 2023-08-28 18:56:38 -07:00
kernel rust: init: remove impl Zeroable for Infallible 2024-05-02 16:32:42 +02:00
macros Rust changes for v6.6 2023-08-29 08:19:46 -07:00
uapi rust: upgrade to Rust 1.68.2 2023-05-31 17:35:03 +02:00
.gitignore rust: support running Rust documentation tests as KUnit ones 2023-07-19 09:32:53 -06:00
bindgen_parameters rust: Ignore preserve-most functions 2024-01-25 15:35:41 -08:00
build_error.rs rust: add build_error crate 2022-12-04 01:59:16 +01:00
compiler_builtins.rs rust: upgrade to Rust 1.73.0 2024-02-16 19:10:43 +01:00
exports.c rust: add build_error crate 2022-12-04 01:59:16 +01:00
helpers.c Rust changes for v6.6 2023-08-29 08:19:46 -07:00
Makefile rust: docs: fix logo replacement 2023-10-19 16:40:00 +02:00