From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> 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/20221019073443.248215-1-chenzhongjin@xxxxxxxxxx/ Reported-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- 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 */
