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Commit 7677fbdf authored by Axel Lin's avatar Axel Lin Committed by Matthew Garrett
Browse files

acer-wmi: fix memory leaks in wmab_execute error path 



When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER, the caller
must kfree the returned buffer if AE_OK is returned.

Call Trace:
wmab_execute
  -> wmi_evaluate_method
    -> acpi_evaluate_object

Thus if callers of wmab_execute() pass ACPI_ALLOCATE_BUFFER, the return
buffer must be kfreed if wmab_execute return AE_OK.

[akpm@linux-foundation.org: avoid multiple return points, remove unneeded cast, remove unneeded initialisation of `status']
Signed-off-by: default avatarAxel Lin <axel.lin@gmail.com>
Acked-by: default avatarCarlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
parent 66904863

drivers/platform/x86/acer-wmi.c

+16 −8
Original line number Diff line number Diff line
@@ -555,6 +555,7 @@ static acpi_status AMW0_find_mailled(void) 
	obj->buffer.length == sizeof(struct wmab_ret)) {

		ret = *((struct wmab_ret *) obj->buffer.pointer);

	} else {

		kfree(out.pointer);

		return AE_ERROR;

	}
@@ -570,7 +571,7 @@ static acpi_status AMW0_set_capabilities(void) 
{

	struct wmab_args args;

	struct wmab_ret ret;

	acpi_status status = AE_OK;

	acpi_status status;

	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *obj;
@@ -593,12 +594,13 @@ static acpi_status AMW0_set_capabilities(void) 
	if (ACPI_FAILURE(status))

		return status;



	obj = (union acpi_object *) out.pointer;

	obj = out.pointer;

	if (obj && obj->type == ACPI_TYPE_BUFFER &&

	obj->buffer.length == sizeof(struct wmab_ret)) {

		ret = *((struct wmab_ret *) obj->buffer.pointer);

	} else {

		return AE_ERROR;

		status = AE_ERROR;

		goto out;

	}



	if (ret.eax & 0x1)
@@ -607,23 +609,26 @@ static acpi_status AMW0_set_capabilities(void) 
	args.ebx = 2 << 8;

	args.ebx |= ACER_AMW0_BLUETOOTH_MASK;



	/*

	 * It's ok to use existing buffer for next wmab_execute call.

	 * But we need to kfree(out.pointer) if next wmab_execute fail.

	 */

	status = wmab_execute(&args, &out);

	if (ACPI_FAILURE(status))

		return status;

		goto out;



	obj = (union acpi_object *) out.pointer;

	if (obj && obj->type == ACPI_TYPE_BUFFER

	&& obj->buffer.length == sizeof(struct wmab_ret)) {

		ret = *((struct wmab_ret *) obj->buffer.pointer);

	} else {

		return AE_ERROR;

		status = AE_ERROR;

		goto out;

	}



	if (ret.eax & 0x1)

		interface->capability |= ACER_CAP_BLUETOOTH;



	kfree(out.pointer);



	/*

	 * This appears to be safe to enable, since all Wistron based laptops

	 * appear to use the same EC register for brightness, even if they
@@ -632,7 +637,10 @@ static acpi_status AMW0_set_capabilities(void) 
	if (quirks->brightness >= 0)

		interface->capability |= ACER_CAP_BRIGHTNESS;



	return AE_OK;

	status = AE_OK;

out:

	kfree(out.pointer);

	return status;

}



static struct wmi_interface AMW0_interface = {