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From:   Yu Liao <liaoyu15@huawei.com>
To:     <hdegoede@redhat.com>, <markgross@kernel.org>
CC:     <liaoyu15@huawei.com>, <airlied@redhat.com>, <mjg@redhat.com>,
        <platform-driver-x86@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <liwei391@huawei.com>
Subject: [PATCH] platform/x86: mxm-wmi: fix memleak in mxm_wmi_call_mx[ds|mx]()
Date:   Tue, 29 Nov 2022 09:11:01 +0800
Message-ID: <20221129011101.2042315-1-liaoyu15@huawei.com>
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Precedence: bulk

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>
---
 drivers/platform/x86/mxm-wmi.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/mxm-wmi.c b/drivers/platform/x86/mxm-wmi.c
index 9a19fbd2f734..9a457956025a 100644
--- 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;
-- 
2.25.1