lkml.org 
[lkml]   [2021]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.10 15/67] can: mcba_usb_start(): add missing urb->transfer_dma initialization
    Date
    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,

    \
     
     \ /
      Last update: 2021-08-02 16:12    [W:4.141 / U:0.112 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site