[PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Nils Lehnen]

From: Benno Lossin <lossin@kernel.org>

All types in `bindings` implement `Zeroable` if they can, so use
`pin_init::zeroed` instead of relying on `unsafe` code.

If this ends up not compiling in the future, something in bindgen or on
the C side changed and is most likely incorrect.

Link: https://lore.kernel.org/r/20250814093046.2071971-8-lossin@kernel.org
Link: https://github.com/Rust-for-Linux/linux/issues/1189
Signed-off-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Nils Lehnen <nils.lehnen@proton.me>
---
Resend of Benno's patch from the Zeroable series [1]: only patches 1, 2
and 11 of that series were applied, and the issue [2] asks for the rest
to be re-sent. Rebased onto rust-next; it applied cleanly, and a
defconfig build with CONFIG_RUST=y and CONFIG_SECURITY=y passes.

Two equivalent one-off patches were posted earlier [3][4]; Miguel asked
in [5] for a resend that keeps Benno's authorship, which this is.
Cc'ing the LSM list per Paul's request on the original thread.

[1] https://lore.kernel.org/r/20250814093046.2071971-1-lossin@kernel.org
[2] https://github.com/Rust-for-Linux/linux/issues/1189
[3] https://lore.kernel.org/r/20251129135657.36144-1-atharvd440@gmail.com
[4] https://lore.kernel.org/r/20260120083824.477339-8-sunke@kylinos.cn
[5] https://lore.kernel.org/r/CANiq72nJqFOR9vhPBfZUNrxU+M1HMV6wN9bN6i8e9rf_oOD2qw@mail.gmail.com

 rust/kernel/security.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/rust/kernel/security.rs b/rust/kernel/security.rs
index 9d271695265f..4dc3eba6ce84 100644
--- a/rust/kernel/security.rs
+++ b/rust/kernel/security.rs
@@ -62,8 +62,7 @@ impl SecurityCtx {
     /// Get the security context given its id.
     #[inline]
     pub fn from_secid(secid: u32) -> Result<Self> {
-        // SAFETY: `struct lsm_context` can be initialized to all zeros.
-        let mut ctx: bindings::lsm_context = unsafe { core::mem::zeroed() };
+        let mut ctx: bindings::lsm_context = pin_init::zeroed();
 
         // SAFETY: Just a C FFI call. The pointer is valid for writes.
         to_result(unsafe { bindings::security_secid_to_secctx(secid, &mut ctx) })?;

base-commit: 73e3f0710014fe6d4ed98cfc02292f6121db7558
-- 
2.43.0

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Miguel Ojeda]

On Fri, Aug 28, 2026 at 4:44 AM Nils Lehnen <nils.lehnen@proton.me> wrote:
>
> Two equivalent one-off patches were posted earlier [3][4]; Miguel asked
> in [5] for a resend that keeps Benno's authorship, which this is.
> Cc'ing the LSM list per Paul's request on the original thread.

Looks good, thanks!

Nit: nowadays we typically use a:

  Link: https://patch.msgid.link/...

to refer to a patch that was picked from the mailing list (usually
written on top of your Signed-off-by) -- `b4` can do it for you
automatically.

But no need to resend just for that, of course (and Paul/I/we can/may
change it when it gets applied :)

Cheers,
Miguel

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Paul Moore]

On Fri, Aug 28, 2026 at 2:15 AM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
> On Fri, Aug 28, 2026 at 4:44 AM Nils Lehnen <nils.lehnen@proton.me> wrote:
> >
> > Two equivalent one-off patches were posted earlier [3][4]; Miguel asked
> > in [5] for a resend that keeps Benno's authorship, which this is.
> > Cc'ing the LSM list per Paul's request on the original thread.
>
> Looks good, thanks!
>
> Nit: nowadays we typically use a:
>
>   Link: https://patch.msgid.link/...
>
> to refer to a patch that was picked from the mailing list (usually
> written on top of your Signed-off-by) -- `b4` can do it for you
> automatically.
>
> But no need to resend just for that, of course (and Paul/I/we can/may
> change it when it gets applied :)

Looks fine to me, I'm assuming the Rust folks would prefer to take this patch?

-- 
paul-moore.com

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Miguel Ojeda]

On Wed, Sep 9, 2026 at 11:51 PM Paul Moore <paul@paul-moore.com> wrote:
>
> Looks fine to me, I'm assuming the Rust folks would prefer to take this patch?

Up to you! If usually patches go through your tree, then that is fine;
otherwise, I am happy to take it of course (ideally with an Acked-by).

Thanks!

Cheers,
Miguel

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Paul Moore]

On Wed, Sep 9, 2026 at 6:43 PM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
> On Wed, Sep 9, 2026 at 11:51 PM Paul Moore <paul@paul-moore.com> wrote:
> >
> > Looks fine to me, I'm assuming the Rust folks would prefer to take this patch?
>
> Up to you! If usually patches go through your tree, then that is fine;
> otherwise, I am happy to take it of course (ideally with an Acked-by).

I'm not sure we have a "usually" yet with the Rust LSM glue code, but
I'm happy to take this patch :)

Since you've already reviewed it, can I add your Reviewed-by tag?

-- 
paul-moore.com

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Miguel Ojeda]

On Thu, Sep 10, 2026 at 4:20 PM Paul Moore <paul@paul-moore.com> wrote:
>
> I'm not sure we have a "usually" yet with the Rust LSM glue code, but
> I'm happy to take this patch :)
>
> Since you've already reviewed it, can I add your Reviewed-by tag?

Sure!

Reviewed-by: Miguel Ojeda <ojeda@kernel.org>

Cheers,
Miguel

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Alice Ryhl]

On Fri, Aug 28, 2026 at 4:44 AM Nils Lehnen <nils.lehnen@proton.me> wrote:
>
> From: Benno Lossin <lossin@kernel.org>
>
> All types in `bindings` implement `Zeroable` if they can, so use
> `pin_init::zeroed` instead of relying on `unsafe` code.
>
> If this ends up not compiling in the future, something in bindgen or on
> the C side changed and is most likely incorrect.
>
> Link: https://lore.kernel.org/r/20250814093046.2071971-8-lossin@kernel.org
> Link: https://github.com/Rust-for-Linux/linux/issues/1189
> Signed-off-by: Benno Lossin <lossin@kernel.org>
> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
> Signed-off-by: Nils Lehnen <nils.lehnen@proton.me>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>

Re: [PATCH] rust: security: replace `core::mem::zeroed` with `pin_init::zeroed`

[Paul Moore]

On Aug 27, 2026 Nils Lehnen <nils.lehnen@proton.me> wrote:
> 
> All types in `bindings` implement `Zeroable` if they can, so use
> `pin_init::zeroed` instead of relying on `unsafe` code.
> 
> If this ends up not compiling in the future, something in bindgen or on
> the C side changed and is most likely incorrect.
> 
> Link: https://lore.kernel.org/r/20250814093046.2071971-8-lossin@kernel.org
> Link: https://github.com/Rust-for-Linux/linux/issues/1189
> Signed-off-by: Benno Lossin <lossin@kernel.org>
> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
> Signed-off-by: Nils Lehnen <nils.lehnen@proton.me>
> Link: https://patch.msgid.link/...
> Reviewed-by: Alice Ryhl <aliceryhl@google.com>
> Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
> Reviewed-by: Gary Guo <gary@garyguo.net>
> ---
> Resend of Benno's patch from the Zeroable series [1]: only patches 1, 2
> and 11 of that series were applied, and the issue [2] asks for the rest
> to be re-sent. Rebased onto rust-next; it applied cleanly, and a
> defconfig build with CONFIG_RUST=y and CONFIG_SECURITY=y passes.
> 
> Two equivalent one-off patches were posted earlier [3][4]; Miguel asked
> in [5] for a resend that keeps Benno's authorship, which this is.
> Cc'ing the LSM list per Paul's request on the original thread.
> 
> [1] https://lore.kernel.org/r/20250814093046.2071971-1-lossin@kernel.org
> [2] https://github.com/Rust-for-Linux/linux/issues/1189
> [3] https://lore.kernel.org/r/20251129135657.36144-1-atharvd440@gmail.com
> [4] https://lore.kernel.org/r/20260120083824.477339-8-sunke@kylinos.cn
> [5] https://lore.kernel.org/r/CANiq72nJqFOR9vhPBfZUNrxU+M1HMV6wN9bN6i8e9rf_oOD2qw@mail.gmail.com
> 
>  rust/kernel/security.rs | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Merged into lsm/dev, thanks everyone!

--
paul-moore.com