2022-11-07 17:53:31

by Rafael J. Wysocki

Subject: [PATCH] ACPICA: Fix error code path in acpi_ds_call_control_method()

From: Rafael J. Wysocki <[email protected]>

A use-after-free in acpi_ps_parse_aml() after a failing invocaion of
acpi_ds_call_control_method() is reported by KASAN [1] and code
inspection reveals that next_walk_state pushed to the thread by
acpi_ds_create_walk_state() is freed on errors, but it is not popped
from the thread beforehand. Thus acpi_ds_get_current_walk_state()
called by acpi_ps_parse_aml() subsequently returns it as the new
walk state which is incorrect.

To address this, make acpi_ds_call_control_method() call
acpi_ds_pop_walk_state() to pop next_walk_state from the thread before
returning an error.

Link: https://lore.kernel.org/linux-acpi/[email protected]/
Reported-by: Chen Zhongjin <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
drivers/acpi/acpica/dsmethod.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

Index: linux-pm/drivers/acpi/acpica/dsmethod.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpica/dsmethod.c
+++ linux-pm/drivers/acpi/acpica/dsmethod.c
@@ -517,7 +517,7 @@ acpi_ds_call_control_method(struct acpi_
info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
if (!info) {
status = AE_NO_MEMORY;
- goto cleanup;
+ goto pop_walk_state;
}

info->parameters = &this_walk_state->operands[0];
@@ -529,7 +529,7 @@ acpi_ds_call_control_method(struct acpi_

ACPI_FREE(info);
if (ACPI_FAILURE(status)) {
- goto cleanup;
+ goto pop_walk_state;
}

next_walk_state->method_nesting_depth =
@@ -575,6 +575,12 @@ acpi_ds_call_control_method(struct acpi_

return_ACPI_STATUS(status);

+pop_walk_state:
+
+ /* On error, pop the walk state to be deleted from thread */
+
+ acpi_ds_pop_walk_state(thread);
+
cleanup:

/* On error, we must terminate the method properly */

2022-11-08 01:55:23

by Chen Zhongjin

Subject: Re: [PATCH] ACPICA: Fix error code path in acpi_ds_call_control_method()

On 2022/11/8 1:42, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <[email protected]>
>
> A use-after-free in acpi_ps_parse_aml() after a failing invocaion of
> acpi_ds_call_control_method() is reported by KASAN [1] and code
> inspection reveals that next_walk_state pushed to the thread by
> acpi_ds_create_walk_state() is freed on errors, but it is not popped
> from the thread beforehand. Thus acpi_ds_get_current_walk_state()
> called by acpi_ps_parse_aml() subsequently returns it as the new
> walk state which is incorrect.
>
> To address this, make acpi_ds_call_control_method() call
> acpi_ds_pop_walk_state() to pop next_walk_state from the thread before
> returning an error.
>
> Link: https://lore.kernel.org/linux-acpi/[email protected]/
> Reported-by: Chen Zhongjin <[email protected]>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---
> drivers/acpi/acpica/dsmethod.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> Index: linux-pm/drivers/acpi/acpica/dsmethod.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/acpica/dsmethod.c
> +++ linux-pm/drivers/acpi/acpica/dsmethod.c
> @@ -517,7 +517,7 @@ acpi_ds_call_control_method(struct acpi_
> info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
> if (!info) {
> status = AE_NO_MEMORY;
> - goto cleanup;
> + goto pop_walk_state;
> }
>
> info->parameters = &this_walk_state->operands[0];
> @@ -529,7 +529,7 @@ acpi_ds_call_control_method(struct acpi_
>
> ACPI_FREE(info);
> if (ACPI_FAILURE(status)) {
> - goto cleanup;
> + goto pop_walk_state;
> }
>
> next_walk_state->method_nesting_depth =
> @@ -575,6 +575,12 @@ acpi_ds_call_control_method(struct acpi_
>
> return_ACPI_STATUS(status);
>
> +pop_walk_state:
> +
> + /* On error, pop the walk state to be deleted from thread */
> +
> + acpi_ds_pop_walk_state(thread);
> +
> cleanup:
>
> /* On error, we must terminate the method properly */
>
>
LGTM

Reviewed-by: Chen Zhongjin <[email protected]>