[PATCH] ACPICA: DEBUGGER: Add return value check to acpi_db_walk_for_fields()

[PATCH] ACPICA: DEBUGGER: Add return value check to acpi_db_walk_for_fields()

[shenzijun]

From: Zijun Shen <shenzijun@kylinos.cn>

The function acpi_db_walk_for_fields frees buffer.pointer by the
first ACPI_FREE. And then uses the second ACPI_FREE to free
buffer.pointer which may assigns again in acpi_evaluate_object.
It's necessary to make sure that buffer.pointer get a block of
memory in acpi_evaluate_object and acpi_evaluate_object return 0.

Signed-off-by: Zijun Shen <shenzijun@kylinos.cn>
---
 drivers/acpi/acpica/dbnames.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/acpica/dbnames.c b/drivers/acpi/acpica/dbnames.c
index 3615e1a6efd8..7a2d980cb2b8 100644
--- a/drivers/acpi/acpica/dbnames.c
+++ b/drivers/acpi/acpica/dbnames.c
@@ -550,7 +550,10 @@ 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)) {
+		return (AE_OK);
+	}
 
 	/*
 	 * Since this is a field unit, surround the output in braces
-- 
2.31.1

Re: [PATCH] ACPICA: DEBUGGER: Add return value check to acpi_db_walk_for_fields()

[Rafael J. Wysocki]

On Wed, Dec 29, 2021 at 10:41 AM shenzijun <shenzijun@kylinos.cn> wrote:
>
> From: Zijun Shen <shenzijun@kylinos.cn>
>
> The function acpi_db_walk_for_fields frees buffer.pointer by the
> first ACPI_FREE. And then uses the second ACPI_FREE to free
> buffer.pointer which may assigns again in acpi_evaluate_object.
> It's necessary to make sure that buffer.pointer get a block of
> memory in acpi_evaluate_object and acpi_evaluate_object return 0.
>
> Signed-off-by: Zijun Shen <shenzijun@kylinos.cn>
> ---
>  drivers/acpi/acpica/dbnames.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/acpica/dbnames.c b/drivers/acpi/acpica/dbnames.c
> index 3615e1a6efd8..7a2d980cb2b8 100644
> --- a/drivers/acpi/acpica/dbnames.c
> +++ b/drivers/acpi/acpica/dbnames.c
> @@ -550,7 +550,10 @@ 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)) {
> +               return (AE_OK);
> +       }
>
>         /*
>          * Since this is a field unit, surround the output in braces
> --


This is ACPICA material, so please submit it to the upstream ACPICA
project via https://github.com/acpica/acpica/

Thanks!