platform/x86: mxm-wmi: fix memleak in mxm_wmi_call_mx[ds|mx]()

[ Upstream commit 727cc0147f5066e359aca65cc6cc5e6d64cc15d8 ]

The ACPI buffer memory (out.pointer) returned by wmi_evaluate_method()
is not freed after the call, so it leads to memory leak.

The method results in ACPI buffer is not used, so just pass NULL to
wmi_evaluate_method() which fixes the memory leak.

Fixes: 99b38b4acc0d ("platform/x86: add MXM WMI driver.")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Link: https://lore.kernel.org/r/20221129011101.2042315-1-liaoyu15@huawei.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/platform/x86/mxm-wmi.c b/drivers/platform/x86/mxm-wmi.c
index 9a19fbd..9a45795 100644 (file)
--- a/drivers/platform/x86/mxm-wmi.c
+++ b/drivers/platform/x86/mxm-wmi.c
@@ -35,13 +35,11 @@ int mxm_wmi_call_mxds(int adapter)
                .xarg = 1,
        };
        struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
-       struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        acpi_status status;
 
        printk("calling mux switch %d\n", adapter);
 
-       status = wmi_evaluate_method(MXM_WMMX_GUID, 0x0, adapter, &input,
-                                    &output);
+       status = wmi_evaluate_method(MXM_WMMX_GUID, 0x0, adapter, &input, NULL);
 
        if (ACPI_FAILURE(status))
                return status;
@@ -60,13 +58,11 @@ int mxm_wmi_call_mxmx(int adapter)
                .xarg = 1,
        };
        struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
-       struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        acpi_status status;
 
        printk("calling mux switch %d\n", adapter);
 
-       status = wmi_evaluate_method(MXM_WMMX_GUID, 0x0, adapter, &input,
-                                    &output);
+       status = wmi_evaluate_method(MXM_WMMX_GUID, 0x0, adapter, &input, NULL);
 
        if (ACPI_FAILURE(status))
                return status;