USB: cdc-wdm: cannot use dev_printk when device is gone
We cannot dereference a removed USB interface for
dev_printk. Use pr_debug instead where necessary.
Flush errors are expected if device is unplugged and are
therefore best ingored at this point.
Move the kill_urbs() call in wdm_release with dev_dbg()
for the non disconnect, as we know it has already been
called if WDM_DISCONNECTING is set. This does not
actually fix anything, but keeps the code more consistent.
Cc: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 7652275..90bc916 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -533,7 +533,9 @@
struct wdm_device *desc = file->private_data;
wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
- if (desc->werr < 0)
+
+ /* cannot dereference desc->intf if WDM_DISCONNECTING */
+ if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
dev_err(&desc->intf->dev, "Error in flush path: %d\n",
desc->werr);
@@ -625,12 +627,13 @@
mutex_unlock(&desc->wlock);
if (!desc->count) {
- dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
- kill_urbs(desc);
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
+ kill_urbs(desc);
desc->manage_power(desc->intf, 0);
} else {
- dev_dbg(&desc->intf->dev, "%s: device gone - cleaning up\n", __func__);
+ /* must avoid dev_printk here as desc->intf is invalid */
+ pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
cleanup(desc);
}
}