Boqun Feng f9275893b0 rust: macros: provide correct provenance when constructing THIS_MODULE ... commit a5a3c952e82c1ada12bf8c55b73af26f1a454bd2 upstream. Currently while defining `THIS_MODULE` symbol in `module!()`, the pointer used to construct `ThisModule` is derived from an immutable reference of `__this_module`, which means the pointer doesn't have the provenance for writing, and that means any write to that pointer is UB regardless of data races or not. However, the usage of `THIS_MODULE` includes passing this pointer to functions that may write to it (probably in unsafe code), and this will create soundness issues. One way to fix this is using `addr_of_mut!()` but that requires the unstable feature "const_mut_refs". So instead of `addr_of_mut()!`, an extern static `Opaque` is used here: since `Opaque<T>` is transparent to `T`, an extern static `Opaque` will just wrap the C symbol (defined in a C compile unit) in an `Opaque`, which provides a pointer with writable provenance via `Opaque::get()`. This fix the potential UBs because of pointer provenance unmatched. Reported-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Closes: 465412664 Fixes: 1fbde52bde ("rust: add `macros` crate") Cc: stable@vger.kernel.org # 6.6.x: be2ca1e03965: ("rust: types: Make Opaque::get const") Link: https://lore.kernel.org/r/20240828180129.4046355-1-boqun.feng@gmail.com [ Fixed two typos, reworded title. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-09-12 11:11:25 +02:00
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concat_idents.rs	rust: macros: add concat_idents! proc macro	2022-12-04 01:59:04 +01:00
helpers.rs	rust: macros: refactor generics parsing of #[pin_data] into its own function	2023-05-31 18:53:09 +02:00
lib.rs	rust: remove params from module macro example	2024-05-02 16:32:42 +02:00
module.rs	rust: macros: provide correct provenance when constructing THIS_MODULE	2024-09-12 11:11:25 +02:00
paste.rs	rust: macros: add paste! proc macro	2023-08-10 22:28:02 +02:00
pin_data.rs	rust: macros: replace Self with the concrete type in #[pin_data]	2023-05-31 18:53:09 +02:00
pinned_drop.rs	rust: init: add PinnedDrop trait and macros	2023-04-12 18:41:05 +02:00
quote.rs	rust: add derive macro for Zeroable	2023-08-21 14:31:48 +02:00
vtable.rs	rust: macros: vtable: fix HAS_* redefinition (gen_const_name)	2023-08-09 21:15:07 +02:00
zeroable.rs	rust: add derive macro for Zeroable	2023-08-21 14:31:48 +02:00