[PATCH 09/11] Input: ims-pcu - fix DMA mapping violation in line setup

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

In ims_pcu_line_setup(), the driver uses pcu->cmd_buf as a transfer
buffer for usb_control_msg(). However, pcu->cmd_buf is embedded in the
struct ims_pcu allocation, which violates DMA mapping rules regarding
cacheline alignment.

Use a heap-allocated buffer for the line coding data instead.

Fixes: 628329d52474 ("Input: add IMS Passenger Control Unit driver")
Cc: stable@vger.kernel.org
Reported-by: Sashiko bot <sashiko-bot@kernel.org>
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/misc/ims-pcu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
index 23e576500890..3b119bc81c85 100644
--- a/drivers/input/misc/ims-pcu.c
+++ b/drivers/input/misc/ims-pcu.c
@@ -1790,11 +1790,16 @@ static void ims_pcu_stop_io(struct ims_pcu *pcu)
 static int ims_pcu_line_setup(struct ims_pcu *pcu)
 {
 	struct usb_host_interface *interface = pcu->ctrl_intf->cur_altsetting;
-	struct usb_cdc_line_coding *line = (void *)pcu->cmd_buf;
+	struct usb_cdc_line_coding *line __free(kfree) =
+				kmalloc(sizeof(*line), GFP_KERNEL);
 	int error;
 
-	memset(line, 0, sizeof(*line));
+	if (!line)
+		return -ENOMEM;
+
 	line->dwDTERate = cpu_to_le32(57600);
+	line->bCharFormat = USB_CDC_1_STOP_BITS;
+	line->bParityType = USB_CDC_NO_PARITY;
 	line->bDataBits = 8;
 
 	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
-- 
2.54.0.746.g67dd491aae-goog