Re: [PATCH] rust_binder: check context manager before creating node

[Greg Kroah-Hartman]

On Thu, Jun 18, 2026 at 03:50:30AM +0530, Keshav Verma wrote:
> Rust Binder currently creates the Binder node before checking
> whether a context manager is already registered. If a context manager already
> exists, set_manager_node() returns -EBUSY after node state has already been
> created.

Odd line-wrapping :(

> 
> Add a check before creating the node to match the C Binder ordering for
> the common already registered case. Keep the final checks in set_manager_node()
> so races with another caller are still handled after node creation.
> 
> Signed-off-by: Keshav Verma <iganschel@xxxxxxxxx>

What commit id does this "fix"?

> ---
>  drivers/android/binder/context.rs | 20 ++++++++++++++++++++
>  drivers/android/binder/process.rs |  1 +
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/android/binder/context.rs b/drivers/android/binder/context.rs
> index ddddb66b3557..562fb339b31f 100644
> --- a/drivers/android/binder/context.rs
> +++ b/drivers/android/binder/context.rs
> @@ -4,6 +4,7 @@
>  
>  use kernel::{
>      alloc::kvec::KVVec,
> +    cred::Credential,
>      error::code::*,
>      prelude::*,
>      security,
> @@ -107,6 +108,25 @@ pub(crate) fn deregister_process(self: &Arc<Self>, proc: &Arc<Process>) {
>          }
>      }
>  
> +    pub(crate) fn check_manager(&self, cred: &Credential) -> Result {
> +        let manager = self.manager.lock();
> +        if manager.node.is_some() {
> +            pr_warn!("BINDER_SET_CONTEXT_MGR already set");

How can this be triggered?

thanks,

greg k-h