lkml.org 
[lkml]   [2020]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 81/86] USB: serial: cyberjack: fix write-URB completion race
    Date
    From: Johan Hovold <johan@kernel.org>

    commit 985616f0457d9f555fff417d0da56174f70cc14f upstream.

    The write-URB busy flag was being cleared before the completion handler
    was done with the URB, something which could lead to corrupt transfers
    due to a racing write request if the URB is resubmitted.

    Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
    Cc: stable <stable@vger.kernel.org> # 2.6.13
    Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Johan Hovold <johan@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/usb/serial/cyberjack.c | 7 ++++++-
    1 file changed, 6 insertions(+), 1 deletion(-)

    --- a/drivers/usb/serial/cyberjack.c
    +++ b/drivers/usb/serial/cyberjack.c
    @@ -368,11 +368,12 @@ static void cyberjack_write_bulk_callbac
    struct cyberjack_private *priv = usb_get_serial_port_data(port);
    struct device *dev = &port->dev;
    int status = urb->status;
    + bool resubmitted = false;

    - set_bit(0, &port->write_urbs_free);
    if (status) {
    dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
    __func__, status);
    + set_bit(0, &port->write_urbs_free);
    return;
    }

    @@ -405,6 +406,8 @@ static void cyberjack_write_bulk_callbac
    goto exit;
    }

    + resubmitted = true;
    +
    dev_dbg(dev, "%s - priv->wrsent=%d\n", __func__, priv->wrsent);
    dev_dbg(dev, "%s - priv->wrfilled=%d\n", __func__, priv->wrfilled);

    @@ -421,6 +424,8 @@ static void cyberjack_write_bulk_callbac

    exit:
    spin_unlock(&priv->lock);
    + if (!resubmitted)
    + set_bit(0, &port->write_urbs_free);
    usb_serial_port_softint(port);
    }


    \
     
     \ /
      Last update: 2020-11-09 14:43    [W:4.047 / U:0.148 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site