Re: [PATCH] firmware: qcom: uefisecapp: fix efivars registration race

[Bartosz Golaszewski]

On Mon, 20 Jan 2025 at 16:10, Johan Hovold <johan+linaro@xxxxxxxxxx> wrote:
>
> Since the conversion to using the TZ allocator, the efivars service is
> registered before the memory pool has been allocated, something which
> can lead to a NULL-pointer dereference in case of a racing EFI variable
> access.
>
> Make sure that all resources have been set up before registering the
> efivars.
>
> Fixes: 6612103ec35a ("firmware: qcom: qseecom: convert to using the TZ allocator")
> Cc: stable@xxxxxxxxxxxxxxx      # 6.11
> Cc: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

> ---
>
> Note that commit 40289e35ca52 ("firmware: qcom: scm: enable the TZ mem
> allocator") looks equally broken as it allocates the tzmem pool only
> after qcom_scm_is_available() returns true and other driver can start
> making SCM calls.
>
> That one appears to be a bit harder to fix as qcom_tzmem_enable()
> currently depends on SCM being available, but someone should definitely
> look into untangling that mess.
>
> Johan

Yeah, I have it on my TODO list. I'll get to it.

Bartosz