USB fixes for 5.1-rc8/final

Here are some small USB fixes for a bunch of warnings/errors that the
 syzbot has been finding with it's new-found ability to stress-test the
 USB layer.
 
 All of these are tiny, but fix real issues, and are marked for stable as
 well.  All of these have had lots of testing in linux-next as well.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'usb-5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for a bunch of warnings/errors that the
  syzbot has been finding with it's new-found ability to stress-test the
  USB layer.

  All of these are tiny, but fix real issues, and are marked for stable
  as well. All of these have had lots of testing in linux-next as well"

* tag 'usb-5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: w1 ds2490: Fix bug caused by improper use of altsetting array
  USB: yurex: Fix protection fault after device removal
  usb: usbip: fix isoc packet num validation in get_pipe
  USB: core: Fix bug caused by duplicate interface PM usage counter
  USB: dummy-hcd: Fix failure to give back unlinked URBs
  USB: core: Fix unterminated string returned by usb_string()

Documentation/driver-api/usb/power-management.rst

@@ -370,11 +370,15 @@ autosuspend the interface's device.  When the usage counter is = 0
 then the interface is considered to be idle, and the kernel may
 autosuspend the device.
 
-Drivers need not be concerned about balancing changes to the usage
-counter; the USB core will undo any remaining "get"s when a driver
-is unbound from its interface.  As a corollary, drivers must not call
-any of the ``usb_autopm_*`` functions after their ``disconnect``
-routine has returned.
+Drivers must be careful to balance their overall changes to the usage
+counter.  Unbalanced "get"s will remain in effect when a driver is
+unbound from its interface, preventing the device from going into
+runtime suspend should the interface be bound to a driver again.  On
+the other hand, drivers are allowed to achieve this balance by calling
+the ``usb_autopm_*`` functions even after their ``disconnect`` routine
+has returned -- say from within a work-queue routine -- provided they
+retain an active reference to the interface (via ``usb_get_intf`` and
+``usb_put_intf``).
 
 Drivers using the async routines are responsible for their own
 synchronization and mutual exclusion.

drivers/usb/core/driver.c

@@ -473,11 +473,6 @@ static int usb_unbind_interface(struct device *dev)
 		pm_runtime_disable(dev);
 	pm_runtime_set_suspended(dev);
 
-	/* Undo any residual pm_autopm_get_interface_* calls */
-	for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
-		usb_autopm_put_interface_no_suspend(intf);
-	atomic_set(&intf->pm_usage_cnt, 0);
-
 	if (!error)
 		usb_autosuspend_device(udev);
 
@@ -1633,7 +1628,6 @@ void usb_autopm_put_interface(struct usb_interface *intf)
 	int			status;
 
 	usb_mark_last_busy(udev);
-	atomic_dec(&intf->pm_usage_cnt);
 	status = pm_runtime_put_sync(&intf->dev);
 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
 			__func__, atomic_read(&intf->dev.power.usage_count),
@@ -1662,7 +1656,6 @@ void usb_autopm_put_interface_async(struct usb_interface *intf)
 	int			status;
 
 	usb_mark_last_busy(udev);
-	atomic_dec(&intf->pm_usage_cnt);
 	status = pm_runtime_put(&intf->dev);
 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
 			__func__, atomic_read(&intf->dev.power.usage_count),
@@ -1684,7 +1677,6 @@ void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
 	struct usb_device	*udev = interface_to_usbdev(intf);
 
 	usb_mark_last_busy(udev);
-	atomic_dec(&intf->pm_usage_cnt);
 	pm_runtime_put_noidle(&intf->dev);
 }
 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
@@ -1715,8 +1707,6 @@ int usb_autopm_get_interface(struct usb_interface *intf)
 	status = pm_runtime_get_sync(&intf->dev);
 	if (status < 0)
 		pm_runtime_put_sync(&intf->dev);
-	else
-		atomic_inc(&intf->pm_usage_cnt);
 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
 			__func__, atomic_read(&intf->dev.power.usage_count),
 			status);
@@ -1750,8 +1740,6 @@ int usb_autopm_get_interface_async(struct usb_interface *intf)
 	status = pm_runtime_get(&intf->dev);
 	if (status < 0 && status != -EINPROGRESS)
 		pm_runtime_put_noidle(&intf->dev);
-	else
-		atomic_inc(&intf->pm_usage_cnt);
 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
 			__func__, atomic_read(&intf->dev.power.usage_count),
 			status);
@@ -1775,7 +1763,6 @@ void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
 	struct usb_device	*udev = interface_to_usbdev(intf);
 
 	usb_mark_last_busy(udev);
-	atomic_inc(&intf->pm_usage_cnt);
 	pm_runtime_get_noresume(&intf->dev);
 }
 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);

drivers/usb/core/message.c

@@ -820,9 +820,11 @@ int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
 
 	if (dev->state == USB_STATE_SUSPENDED)
 		return -EHOSTUNREACH;
-	if (size <= 0 || !buf || !index)
+	if (size <= 0 || !buf)
 		return -EINVAL;
 	buf[0] = 0;
+	if (index <= 0 || index >= 256)
+		return -EINVAL;
 	tbuf = kmalloc(256, GFP_NOIO);
 	if (!tbuf)
 		return -ENOMEM;

drivers/usb/gadget/udc/dummy_hcd.c

@@ -979,8 +979,18 @@ static int dummy_udc_start(struct usb_gadget *g,
 	struct dummy_hcd	*dum_hcd = gadget_to_dummy_hcd(g);
 	struct dummy		*dum = dum_hcd->dum;
 
-	if (driver->max_speed == USB_SPEED_UNKNOWN)
+	switch (g->speed) {
+	/* All the speeds we support */
+	case USB_SPEED_LOW:
+	case USB_SPEED_FULL:
+	case USB_SPEED_HIGH:
+	case USB_SPEED_SUPER:
+		break;
+	default:
+		dev_err(dummy_dev(dum_hcd), "Unsupported driver max speed %d\n",
+				driver->max_speed);
 		return -EINVAL;
+	}
 
 	/*
 	 * SLAVE side init ... the layer above hardware, which
@@ -1784,9 +1794,10 @@ static void dummy_timer(struct timer_list *t)
 		/* Bus speed is 500000 bytes/ms, so use a little less */
 		total = 490000;
 		break;
-	default:
+	default:	/* Can't happen */
 		dev_err(dummy_dev(dum_hcd), "bogus device speed\n");
-		return;
+		total = 0;
+		break;
 	}
 
 	/* FIXME if HZ != 1000 this will probably misbehave ... */
@@ -1828,7 +1839,7 @@ restart:
 
 		/* Used up this frame's bandwidth? */
 		if (total <= 0)
-			break;
+			continue;
 
 		/* find the gadget's ep for this request (if configured) */
 		address = usb_pipeendpoint (urb->pipe);

drivers/usb/misc/yurex.c

@@ -314,6 +314,7 @@ static void yurex_disconnect(struct usb_interface *interface)
 	usb_deregister_dev(interface, &yurex_class);
 
 	/* prevent more I/O from starting */
+	usb_poison_urb(dev->urb);
 	mutex_lock(&dev->io_mutex);
 	dev->interface = NULL;
 	mutex_unlock(&dev->io_mutex);

drivers/usb/storage/realtek_cr.c

@@ -763,18 +763,16 @@ static void rts51x_suspend_timer_fn(struct timer_list *t)
 		break;
 	case RTS51X_STAT_IDLE:
 	case RTS51X_STAT_SS:
-		usb_stor_dbg(us, "RTS51X_STAT_SS, intf->pm_usage_cnt:%d, power.usage:%d\n",
-			     atomic_read(&us->pusb_intf->pm_usage_cnt),
+		usb_stor_dbg(us, "RTS51X_STAT_SS, power.usage:%d\n",
 			     atomic_read(&us->pusb_intf->dev.power.usage_count));
 
-		if (atomic_read(&us->pusb_intf->pm_usage_cnt) > 0) {
+		if (atomic_read(&us->pusb_intf->dev.power.usage_count) > 0) {
 			usb_stor_dbg(us, "Ready to enter SS state\n");
 			rts51x_set_stat(chip, RTS51X_STAT_SS);
 			/* ignore mass storage interface's children */
 			pm_suspend_ignore_children(&us->pusb_intf->dev, true);
 			usb_autopm_put_interface_async(us->pusb_intf);
-			usb_stor_dbg(us, "RTS51X_STAT_SS 01, intf->pm_usage_cnt:%d, power.usage:%d\n",
-				     atomic_read(&us->pusb_intf->pm_usage_cnt),
+			usb_stor_dbg(us, "RTS51X_STAT_SS 01, power.usage:%d\n",
 				     atomic_read(&us->pusb_intf->dev.power.usage_count));
 		}
 		break;
@@ -807,11 +805,10 @@ static void rts51x_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 	int ret;
 
 	if (working_scsi(srb)) {
-		usb_stor_dbg(us, "working scsi, intf->pm_usage_cnt:%d, power.usage:%d\n",
-			     atomic_read(&us->pusb_intf->pm_usage_cnt),
+		usb_stor_dbg(us, "working scsi, power.usage:%d\n",
 			     atomic_read(&us->pusb_intf->dev.power.usage_count));
 
-		if (atomic_read(&us->pusb_intf->pm_usage_cnt) <= 0) {
+		if (atomic_read(&us->pusb_intf->dev.power.usage_count) <= 0) {
 			ret = usb_autopm_get_interface(us->pusb_intf);
 			usb_stor_dbg(us, "working scsi, ret=%d\n", ret);
 		}

drivers/usb/usbip/stub_rx.c

@@ -361,16 +361,10 @@ static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
 	}
 
 	if (usb_endpoint_xfer_isoc(epd)) {
-		/* validate packet size and number of packets */
-		unsigned int maxp, packets, bytes;
-
-		maxp = usb_endpoint_maxp(epd);
-		maxp *= usb_endpoint_maxp_mult(epd);
-		bytes = pdu->u.cmd_submit.transfer_buffer_length;
-		packets = DIV_ROUND_UP(bytes, maxp);
-
+		/* validate number of packets */
 		if (pdu->u.cmd_submit.number_of_packets < 0 ||
-		    pdu->u.cmd_submit.number_of_packets > packets) {
+		    pdu->u.cmd_submit.number_of_packets >
+		    USBIP_MAX_ISO_PACKETS) {
 			dev_err(&sdev->udev->dev,
 				"CMD_SUBMIT: isoc invalid num packets %d\n",
 				pdu->u.cmd_submit.number_of_packets);

drivers/usb/usbip/usbip_common.h

@@ -121,6 +121,13 @@ extern struct device_attribute dev_attr_usbip_debug;
 #define USBIP_DIR_OUT	0x00
 #define USBIP_DIR_IN	0x01
 
+/*
+ * Arbitrary limit for the maximum number of isochronous packets in an URB,
+ * compare for example the uhci_submit_isochronous function in
+ * drivers/usb/host/uhci-q.c
+ */
+#define USBIP_MAX_ISO_PACKETS 1024
+
 /**
  * struct usbip_header_basic - data pertinent to every request
  * @command: the usbip request type

drivers/w1/masters/ds2490.c

@@ -1016,15 +1016,15 @@ static int ds_probe(struct usb_interface *intf,
 	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
 	alt = 3;
 	err = usb_set_interface(dev->udev,
-		intf->altsetting[alt].desc.bInterfaceNumber, alt);
+		intf->cur_altsetting->desc.bInterfaceNumber, alt);
 	if (err) {
 		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
 			"for %d interface: err=%d.\n", alt,
-			intf->altsetting[alt].desc.bInterfaceNumber, err);
+			intf->cur_altsetting->desc.bInterfaceNumber, err);
 		goto err_out_clear;
 	}
 
-	iface_desc = &intf->altsetting[alt];
+	iface_desc = intf->cur_altsetting;
 	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
 		pr_info("Num endpoints=%d. It is not DS9490R.\n",
 			iface_desc->desc.bNumEndpoints);

include/linux/usb.h

@@ -200,7 +200,6 @@ usb_find_last_int_out_endpoint(struct usb_host_interface *alt,
  * @dev: driver model's view of this device
  * @usb_dev: if an interface is bound to the USB major, this will point
  *	to the sysfs representation for that device.
- * @pm_usage_cnt: PM usage counter for this interface
  * @reset_ws: Used for scheduling resets from atomic context.
  * @resetting_device: USB core reset the device, so use alt setting 0 as
  *	current; needs bandwidth alloc after reset.
@@ -257,7 +256,6 @@ struct usb_interface {
 
 	struct device dev;		/* interface specific device info */
 	struct device *usb_dev;
-	atomic_t pm_usage_cnt;		/* usage counter for autosuspend */
 	struct work_struct reset_ws;	/* for resets in atomic context */
 };
 #define	to_usb_interface(d) container_of(d, struct usb_interface, dev)