Re: [PATCH v2 3/3] kasan: rust: Add KASAN smoke test via UAF

[Matthew Maurer <mmaurer@google.com>]

> diff --git a/mm/kasan/kasan_test_rust.rs b/mm/kasan/kasan_test_rust.rs
> new file mode 100644
> index 000000000000..6f4b43ea488c
> --- /dev/null
> +++ b/mm/kasan/kasan_test_rust.rs
> @@ -0,0 +1,17 @@

Realized right after sending there should be
// SPDX-License-Identifier: GPL-2.0
here. It should be added before merging, but not re-sending to avoid spam.

> +//! Helper crate for KASAN testing
> +//! Provides behavior to check the sanitization of Rust code.
> +use kernel::prelude::*;
> +use core::ptr::addr_of_mut;
> +
> +/// Trivial UAF - allocate a big vector, grab a pointer partway through,
> +/// drop the vector, and touch it.
> +#[no_mangle]
> +pub extern "C" fn kasan_test_rust_uaf() -> u8 {
> +    let mut v: Vec<u8> = Vec::new();
> +    for _ in 0..4096 {
> +        v.push(0x42, GFP_KERNEL).unwrap();
> +    }
> +    let ptr: *mut u8 = addr_of_mut!(v[2048]);
> +    drop(v);
> +    unsafe { *ptr }
> +}
> --
> 2.46.0.76.ge559c4bf1a-goog
>