Re: [PATCH] tee: optee: allocate a bitmap for all valid notification keys

[Sumit Garg]

On Fri, 09 Oct 2026 at 20:19:48 -0700, Amirreza Zarrabi wrote:
> Notification keys are checked against an inclusive maximum, but
> optee_notif_init() passes that maximum to bitmap_zalloc() as the number of
> bits. The bitmap is therefore one bit short. When the maximum key is a
> multiple of BITS_PER_LONG, accessing that key reads or writes beyond the
> allocated bitmap. Word rounding masks the problem.
>
> Allocate max_key + 1 bits so that the highest valid key has storage.
>
> Fixes: 787c80cc7b22 ("optee: separate notification functions")
> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@xxxxxxxxxxxxxxxx>
> ---
> drivers/tee/optee/notif.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>

-Sumit

> diff --git a/drivers/tee/optee/notif.c b/drivers/tee/optee/notif.c
> index 68014222d7be..2bf5ce397233 100644
> --- a/drivers/tee/optee/notif.c
> +++ b/drivers/tee/optee/notif.c
> @@ -114,7 +114,7 @@ int optee_notif_init(struct optee *optee, u_int max_key)
> {
> 	spin_lock_init(&optee->notif.lock);
> 	INIT_LIST_HEAD(&optee->notif.db);
> -	optee->notif.bitmap = bitmap_zalloc(max_key, GFP_KERNEL);
> +	optee->notif.bitmap = bitmap_zalloc(max_key + 1, GFP_KERNEL);
> 	if (!optee->notif.bitmap)
> 		return -ENOMEM;
>
>
> ---
> base-commit: becb95e45ef0dda9ffb35156d909d3da7a2789c3
> change-id: 20261009-fix-tee-max-keys-50f2db87b4e5
>
> Best regards,
> --
> Amirreza Zarrabi <amirreza.zarrabi@xxxxxxxxxxxxxxxx>