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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Wed, 6 Dec 2023 17:39:29 +0100
Message-ID: <CAJZ5v0i7LYzF13M0qdeYWXZ7uO6HUpAS7pE5RJnOAJtKB8o88A@mail.gmail.com>
Subject: Re: [PATCH] ACPICA: debugger: check status of acpi_evaluate_object in acpi_db_walk_for_fields
To:     Nikita Kiryushin <kiryushin@ancud.ru>
Cc:     Robert Moore <robert.moore@intel.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Len Brown <lenb@kernel.org>,
        Erik Kaneda <erik.kaneda@intel.com>,
        linux-acpi@vger.kernel.org, acpica-devel@lists.linux.dev,
        linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org
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On Mon, Nov 13, 2023 at 2:33 PM Nikita Kiryushin <kiryushin@ancud.ru> wrote:
>
> Errors in acpi_evaluate_object can lead to incorrect state of buffer.
> This can lead to access to data in previously ACPI_FREEd buffer and
> secondary ACPI_FREE to the same buffer later.
>
> Handle errors in acpi_evaluate_object the same way it is done earlier
> with acpi_ns_handle_to_pathname.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: 5fd033288a86 ("ACPICA: debugger: add command to dump all fields
> of particular subtype")
> Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
> ---
>   drivers/acpi/acpica/dbnames.c | 8 ++++++--

This is ACPICA code which comes from a separate project.

The way to change it is to submit a pull request with the desired change
to the upstream ACPICA project on GitHub and add a Link tag pointing
to the upstream PR to the corresponding Linux patch.  Then, the Linux
patch can only be applied after the corresponding upstream PR has been
merged.

Thanks!

>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/acpica/dbnames.c b/drivers/acpi/acpica/dbnames.c
> index b91155ea9c34..c9131259f717 100644
> --- a/drivers/acpi/acpica/dbnames.c
> +++ b/drivers/acpi/acpica/dbnames.c
> @@ -550,8 +550,12 @@ acpi_db_walk_for_fields(acpi_handle obj_handle,
>         ACPI_FREE(buffer.pointer);
>         buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
> -       acpi_evaluate_object(obj_handle, NULL, NULL, &buffer);
> -
> +       status = acpi_evaluate_object(obj_handle, NULL, NULL, &buffer);
> +       if (ACPI_FAILURE(status)) {
> +               acpi_os_printf("Could Not evaluate object %p\n",
> +                              obj_handle);
> +               return (AE_OK);
> +       }
>         /*
>          * Since this is a field unit, surround the output in braces
>          */
> --
> 2.34.1
>
>