USB: cdc-wdm: cannot use dev_printk when device is gone (6b0b79d3) · Commits · 戴 / test

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>

drivers/usb/class/cdc-wdm.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -533,7 +533,9 @@ static int wdm_flush(struct file *file, fl_owner_t id)
		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 @@ static int wdm_release(struct inode inode, struct file file)
		mutex_unlock(&desc->wlock);

		if (!desc->count) {
		if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
		kill_urbs(desc);
		if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
		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);
		}
		}

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