| From fc43fb69a7af92839551f99c1a96a37b77b3ae7a Mon Sep 17 00:00:00 2001 |
| From: Pavel Skripkin <paskripkin@gmail.com> |
| Date: Sun, 25 Jul 2021 13:36:30 +0300 |
| Subject: can: mcba_usb_start(): add missing urb->transfer_dma initialization |
| |
| From: Pavel Skripkin <paskripkin@gmail.com> |
| |
| commit fc43fb69a7af92839551f99c1a96a37b77b3ae7a upstream. |
| |
| Yasushi reported, that his Microchip CAN Analyzer stopped working |
| since commit 91c02557174b ("can: mcba_usb: fix memory leak in |
| mcba_usb"). The problem was in missing urb->transfer_dma |
| initialization. |
| |
| In my previous patch to this driver I refactored mcba_usb_start() code |
| to avoid leaking usb coherent buffers. To archive it, I passed local |
| stack variable to usb_alloc_coherent() and then saved it to private |
| array to correctly free all coherent buffers on ->close() call. But I |
| forgot to initialize urb->transfer_dma with variable passed to |
| usb_alloc_coherent(). |
| |
| All of this was causing device to not work, since dma addr 0 is not |
| valid and following log can be found on bug report page, which points |
| exactly to problem described above. |
| |
| | DMAR: [DMA Write] Request device [00:14.0] PASID ffffffff fault addr 0 [fault reason 05] PTE Write access is not set |
| |
| Fixes: 91c02557174b ("can: mcba_usb: fix memory leak in mcba_usb") |
| Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=990850 |
| Link: https://lore.kernel.org/r/20210725103630.23864-1-paskripkin@gmail.com |
| Cc: linux-stable <stable@vger.kernel.org> |
| Reported-by: Yasushi SHOJI <yasushi.shoji@gmail.com> |
| Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> |
| Tested-by: Yasushi SHOJI <yashi@spacecubics.com> |
| [mkl: fixed typos in commit message - thanks Yasushi SHOJI] |
| Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/can/usb/mcba_usb.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/drivers/net/can/usb/mcba_usb.c |
| +++ b/drivers/net/can/usb/mcba_usb.c |
| @@ -653,6 +653,8 @@ static int mcba_usb_start(struct mcba_pr |
| break; |
| } |
| |
| + urb->transfer_dma = buf_dma; |
| + |
| usb_fill_bulk_urb(urb, priv->udev, |
| usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN), |
| buf, MCBA_USB_RX_BUFF_SIZE, |
