HID: lenovo: Don't use stack variables for DMA buffers (ea36ae09) · Commits · 戴 / test

The lenovo_send_cmd_cptkbd function uses a stack variable to submit commands via hid_hw_raw_request. Eventually this gets to the usb_hcd_map_urb_for_dma function, which causes a warning to be thrown if the CONFIG_DMA_API_DEBUG option is enabled. Fix this by allocating a temporary buffer instead. [jkosina@suse.cz: no need to NULL-initialize buf, spotted by Benjamin] Reported-by:

lejeczek <peljasz@yahoo.co.uk> Signed-off-by:

Josh Boyer <jwboyer@fedoraproject.org> Reviewed-by:

Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by:

Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-lenovo.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -184,21 +184,31 @@ static int lenovo_send_cmd_cptkbd(struct hid_device *hdev,
		unsigned char byte2, unsigned char byte3)
		{
		int ret;
		unsigned char buf[] = {0x18, byte2, byte3};
		unsigned char *buf;

		buf = kzalloc(3, GFP_KERNEL);
		if (!buf)
		return -ENOMEM;

		buf[0] = 0x18;
		buf[1] = byte2;
		buf[2] = byte3;

		switch (hdev->product) {
		case USB_DEVICE_ID_LENOVO_CUSBKBD:
		ret = hid_hw_raw_request(hdev, 0x13, buf, sizeof(buf),
		ret = hid_hw_raw_request(hdev, 0x13, buf, 3,
		HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
		break;
		case USB_DEVICE_ID_LENOVO_CBTKBD:
		ret = hid_hw_output_report(hdev, buf, sizeof(buf));
		ret = hid_hw_output_report(hdev, buf, 3);
		break;
		default:
		ret = -EINVAL;
		break;
		}

		kfree(buf);

		return ret < 0 ? ret : 0; /* BT returns 0, USB returns sizeof(buf) */
		}

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