Merge tag 'usb-4.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are some USB driver fixes fro 4.17-rc6.

  They resolve some reported bugs in the musb driver, the xhci driver,
  and a number of small fixes for the usbip driver.

  All of these have been in linux-next with no reported issues"

* tag 'usb-4.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usbip: usbip_host: fix bad unlock balance during stub_probe()
  usbip: usbip_host: fix NULL-ptr deref and use-after-free errors
  usbip: usbip_host: run rebind from exit when module is removed
  usbip: usbip_host: delete device from busid_table after rebind
  usbip: usbip_host: refine probe and disconnect debug msgs to be useful
  usb: musb: fix remote wakeup racing with suspend
  xhci: Fix USB3 NULL pointer dereference at logical disconnect.

drivers/usb/host/xhci-hub.c

@@ -354,7 +354,7 @@ int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
 
 	slot_id = 0;
 	for (i = 0; i < MAX_HC_SLOTS; i++) {
-		if (!xhci->devs[i])
+		if (!xhci->devs[i] || !xhci->devs[i]->udev)
 			continue;
 		speed = xhci->devs[i]->udev->speed;
 		if (((speed >= USB_SPEED_SUPER) == (hcd->speed >= HCD_USB3))

drivers/usb/musb/musb_host.c

@@ -2524,8 +2524,11 @@ static int musb_bus_suspend(struct usb_hcd *hcd)
 {
 	struct musb	*musb = hcd_to_musb(hcd);
 	u8		devctl;
+	int		ret;
 
-	musb_port_suspend(musb, true);
+	ret = musb_port_suspend(musb, true);
+	if (ret)
+		return ret;
 
 	if (!is_host_active(musb))
 		return 0;

drivers/usb/musb/musb_host.h

@@ -67,7 +67,7 @@ extern void musb_host_rx(struct musb *, u8);
 extern void musb_root_disconnect(struct musb *musb);
 extern void musb_host_resume_root_hub(struct musb *musb);
 extern void musb_host_poke_root_hub(struct musb *musb);
-extern void musb_port_suspend(struct musb *musb, bool do_suspend);
+extern int musb_port_suspend(struct musb *musb, bool do_suspend);
 extern void musb_port_reset(struct musb *musb, bool do_reset);
 extern void musb_host_finish_resume(struct work_struct *work);
 #else
@@ -99,7 +99,10 @@ static inline void musb_root_disconnect(struct musb *musb)	{}
 static inline void musb_host_resume_root_hub(struct musb *musb)	{}
 static inline void musb_host_poll_rh_status(struct musb *musb)	{}
 static inline void musb_host_poke_root_hub(struct musb *musb)	{}
-static inline void musb_port_suspend(struct musb *musb, bool do_suspend) {}
+static inline int musb_port_suspend(struct musb *musb, bool do_suspend)
+{
+	return 0;
+}
 static inline void musb_port_reset(struct musb *musb, bool do_reset) {}
 static inline void musb_host_finish_resume(struct work_struct *work) {}
 #endif

drivers/usb/musb/musb_virthub.c

@@ -48,14 +48,14 @@ void musb_host_finish_resume(struct work_struct *work)
 	spin_unlock_irqrestore(&musb->lock, flags);
 }
 
-void musb_port_suspend(struct musb *musb, bool do_suspend)
+int musb_port_suspend(struct musb *musb, bool do_suspend)
 {
 	struct usb_otg	*otg = musb->xceiv->otg;
 	u8		power;
 	void __iomem	*mbase = musb->mregs;
 
 	if (!is_host_active(musb))
-		return;
+		return 0;
 
 	/* NOTE:  this doesn't necessarily put PHY into low power mode,
 	 * turning off its clock; that's a function of PHY integration and
@@ -66,16 +66,20 @@ void musb_port_suspend(struct musb *musb, bool do_suspend)
 	if (do_suspend) {
 		int retries = 10000;
 
-		power &= ~MUSB_POWER_RESUME;
-		power |= MUSB_POWER_SUSPENDM;
-		musb_writeb(mbase, MUSB_POWER, power);
+		if (power & MUSB_POWER_RESUME)
+			return -EBUSY;
 
-		/* Needed for OPT A tests */
-		power = musb_readb(mbase, MUSB_POWER);
-		while (power & MUSB_POWER_SUSPENDM) {
+		if (!(power & MUSB_POWER_SUSPENDM)) {
+			power |= MUSB_POWER_SUSPENDM;
+			musb_writeb(mbase, MUSB_POWER, power);
+
+			/* Needed for OPT A tests */
 			power = musb_readb(mbase, MUSB_POWER);
-			if (retries-- < 1)
-				break;
+			while (power & MUSB_POWER_SUSPENDM) {
+				power = musb_readb(mbase, MUSB_POWER);
+				if (retries-- < 1)
+					break;
+			}
 		}
 
 		musb_dbg(musb, "Root port suspended, power %02x", power);
@@ -111,6 +115,7 @@ void musb_port_suspend(struct musb *musb, bool do_suspend)
 		schedule_delayed_work(&musb->finish_resume_work,
 				      msecs_to_jiffies(USB_RESUME_TIMEOUT));
 	}
+	return 0;
 }
 
 void musb_port_reset(struct musb *musb, bool do_reset)

drivers/usb/usbip/stub.h

@@ -73,6 +73,7 @@ struct bus_id_priv {
 	struct stub_device *sdev;
 	struct usb_device *udev;
 	char shutdown_busid;
+	spinlock_t busid_lock;
 };
 
 /* stub_priv is allocated from stub_priv_cache */
@@ -83,6 +84,7 @@ extern struct usb_device_driver stub_driver;
 
 /* stub_main.c */
 struct bus_id_priv *get_busid_priv(const char *busid);
+void put_busid_priv(struct bus_id_priv *bid);
 int del_match_busid(char *busid);
 void stub_device_cleanup_urbs(struct stub_device *sdev);
 

drivers/usb/usbip/stub_dev.c

@@ -300,9 +300,9 @@ static int stub_probe(struct usb_device *udev)
 	struct stub_device *sdev = NULL;
 	const char *udev_busid = dev_name(&udev->dev);
 	struct bus_id_priv *busid_priv;
-	int rc;
+	int rc = 0;
 
-	dev_dbg(&udev->dev, "Enter\n");
+	dev_dbg(&udev->dev, "Enter probe\n");
 
 	/* check we should claim or not by busid_table */
 	busid_priv = get_busid_priv(udev_busid);
@@ -317,13 +317,15 @@ static int stub_probe(struct usb_device *udev)
 		 * other matched drivers by the driver core.
 		 * See driver_probe_device() in driver/base/dd.c
 		 */
-		return -ENODEV;
+		rc = -ENODEV;
+		goto call_put_busid_priv;
 	}
 
 	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 		dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 			 udev_busid);
-		return -ENODEV;
+		rc = -ENODEV;
+		goto call_put_busid_priv;
 	}
 
 	if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
@@ -331,13 +333,16 @@ static int stub_probe(struct usb_device *udev)
 			"%s is attached on vhci_hcd... skip!\n",
 			udev_busid);
 
-		return -ENODEV;
+		rc = -ENODEV;
+		goto call_put_busid_priv;
 	}
 
 	/* ok, this is my device */
 	sdev = stub_device_alloc(udev);
-	if (!sdev)
-		return -ENOMEM;
+	if (!sdev) {
+		rc = -ENOMEM;
+		goto call_put_busid_priv;
+	}
 
 	dev_info(&udev->dev,
 		"usbip-host: register new device (bus %u dev %u)\n",
@@ -369,7 +374,9 @@ static int stub_probe(struct usb_device *udev)
 	}
 	busid_priv->status = STUB_BUSID_ALLOC;
 
-	return 0;
+	rc = 0;
+	goto call_put_busid_priv;
+
 err_files:
 	usb_hub_release_port(udev->parent, udev->portnum,
 			     (struct usb_dev_state *) udev);
@@ -379,6 +386,9 @@ err_port:
 
 	busid_priv->sdev = NULL;
 	stub_device_free(sdev);
+
+call_put_busid_priv:
+	put_busid_priv(busid_priv);
 	return rc;
 }
 
@@ -404,7 +414,7 @@ static void stub_disconnect(struct usb_device *udev)
 	struct bus_id_priv *busid_priv;
 	int rc;
 
-	dev_dbg(&udev->dev, "Enter\n");
+	dev_dbg(&udev->dev, "Enter disconnect\n");
 
 	busid_priv = get_busid_priv(udev_busid);
 	if (!busid_priv) {
@@ -417,7 +427,7 @@ static void stub_disconnect(struct usb_device *udev)
 	/* get stub_device */
 	if (!sdev) {
 		dev_err(&udev->dev, "could not get device");
-		return;
+		goto call_put_busid_priv;
 	}
 
 	dev_set_drvdata(&udev->dev, NULL);
@@ -432,12 +442,12 @@ static void stub_disconnect(struct usb_device *udev)
 				  (struct usb_dev_state *) udev);
 	if (rc) {
 		dev_dbg(&udev->dev, "unable to release port\n");
-		return;
+		goto call_put_busid_priv;
 	}
 
 	/* If usb reset is called from event handler */
 	if (usbip_in_eh(current))
-		return;
+		goto call_put_busid_priv;
 
 	/* shutdown the current connection */
 	shutdown_busid(busid_priv);
@@ -448,12 +458,11 @@ static void stub_disconnect(struct usb_device *udev)
 	busid_priv->sdev = NULL;
 	stub_device_free(sdev);
 
-	if (busid_priv->status == STUB_BUSID_ALLOC) {
+	if (busid_priv->status == STUB_BUSID_ALLOC)
 		busid_priv->status = STUB_BUSID_ADDED;
-	} else {
-		busid_priv->status = STUB_BUSID_OTHER;
-		del_match_busid((char *)udev_busid);
-	}
+
+call_put_busid_priv:
+	put_busid_priv(busid_priv);
 }
 
 #ifdef CONFIG_PM

drivers/usb/usbip/stub_main.c

@@ -14,6 +14,7 @@
 #define DRIVER_DESC "USB/IP Host Driver"
 
 struct kmem_cache *stub_priv_cache;
+
 /*
  * busid_tables defines matching busids that usbip can grab. A user can change
  * dynamically what device is locally used and what device is exported to a
@@ -25,6 +26,8 @@ static spinlock_t busid_table_lock;
 
 static void init_busid_table(void)
 {
+	int i;
+
 	/*
 	 * This also sets the bus_table[i].status to
 	 * STUB_BUSID_OTHER, which is 0.
@@ -32,6 +35,9 @@ static void init_busid_table(void)
 	memset(busid_table, 0, sizeof(busid_table));
 
 	spin_lock_init(&busid_table_lock);
+
+	for (i = 0; i < MAX_BUSID; i++)
+		spin_lock_init(&busid_table[i].busid_lock);
 }
 
 /*
@@ -43,15 +49,20 @@ static int get_busid_idx(const char *busid)
 	int i;
 	int idx = -1;
 
-	for (i = 0; i < MAX_BUSID; i++)
+	for (i = 0; i < MAX_BUSID; i++) {
+		spin_lock(&busid_table[i].busid_lock);
 		if (busid_table[i].name[0])
 			if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
 				idx = i;
+				spin_unlock(&busid_table[i].busid_lock);
 				break;
 			}
+		spin_unlock(&busid_table[i].busid_lock);
+	}
 	return idx;
 }
 
+/* Returns holding busid_lock. Should call put_busid_priv() to unlock */
 struct bus_id_priv *get_busid_priv(const char *busid)
 {
 	int idx;
@@ -59,13 +70,22 @@ struct bus_id_priv *get_busid_priv(const char *busid)
 
 	spin_lock(&busid_table_lock);
 	idx = get_busid_idx(busid);
-	if (idx >= 0)
+	if (idx >= 0) {
 		bid = &(busid_table[idx]);
+		/* get busid_lock before returning */
+		spin_lock(&bid->busid_lock);
+	}
 	spin_unlock(&busid_table_lock);
 
 	return bid;
 }
 
+void put_busid_priv(struct bus_id_priv *bid)
+{
+	if (bid)
+		spin_unlock(&bid->busid_lock);
+}
+
 static int add_match_busid(char *busid)
 {
 	int i;
@@ -78,15 +98,19 @@ static int add_match_busid(char *busid)
 		goto out;
 	}
 
-	for (i = 0; i < MAX_BUSID; i++)
+	for (i = 0; i < MAX_BUSID; i++) {
+		spin_lock(&busid_table[i].busid_lock);
 		if (!busid_table[i].name[0]) {
 			strlcpy(busid_table[i].name, busid, BUSID_SIZE);
 			if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
 			    (busid_table[i].status != STUB_BUSID_REMOV))
 				busid_table[i].status = STUB_BUSID_ADDED;
 			ret = 0;
+			spin_unlock(&busid_table[i].busid_lock);
 			break;
 		}
+		spin_unlock(&busid_table[i].busid_lock);
+	}
 
 out:
 	spin_unlock(&busid_table_lock);
@@ -107,6 +131,8 @@ int del_match_busid(char *busid)
 	/* found */
 	ret = 0;
 
+	spin_lock(&busid_table[idx].busid_lock);
+
 	if (busid_table[idx].status == STUB_BUSID_OTHER)
 		memset(busid_table[idx].name, 0, BUSID_SIZE);
 
@@ -114,6 +140,7 @@ int del_match_busid(char *busid)
 	    (busid_table[idx].status != STUB_BUSID_ADDED))
 		busid_table[idx].status = STUB_BUSID_REMOV;
 
+	spin_unlock(&busid_table[idx].busid_lock);
 out:
 	spin_unlock(&busid_table_lock);
 
@@ -126,9 +153,12 @@ static ssize_t match_busid_show(struct device_driver *drv, char *buf)
 	char *out = buf;
 
 	spin_lock(&busid_table_lock);
-	for (i = 0; i < MAX_BUSID; i++)
+	for (i = 0; i < MAX_BUSID; i++) {
+		spin_lock(&busid_table[i].busid_lock);
 		if (busid_table[i].name[0])
 			out += sprintf(out, "%s ", busid_table[i].name);
+		spin_unlock(&busid_table[i].busid_lock);
+	}
 	spin_unlock(&busid_table_lock);
 	out += sprintf(out, "\n");
 
@@ -169,6 +199,51 @@ static ssize_t match_busid_store(struct device_driver *dev, const char *buf,
 }
 static DRIVER_ATTR_RW(match_busid);
 
+static int do_rebind(char *busid, struct bus_id_priv *busid_priv)
+{
+	int ret;
+
+	/* device_attach() callers should hold parent lock for USB */
+	if (busid_priv->udev->dev.parent)
+		device_lock(busid_priv->udev->dev.parent);
+	ret = device_attach(&busid_priv->udev->dev);
+	if (busid_priv->udev->dev.parent)
+		device_unlock(busid_priv->udev->dev.parent);
+	if (ret < 0) {
+		dev_err(&busid_priv->udev->dev, "rebind failed\n");
+		return ret;
+	}
+	return 0;
+}
+
+static void stub_device_rebind(void)
+{
+#if IS_MODULE(CONFIG_USBIP_HOST)
+	struct bus_id_priv *busid_priv;
+	int i;
+
+	/* update status to STUB_BUSID_OTHER so probe ignores the device */
+	spin_lock(&busid_table_lock);
+	for (i = 0; i < MAX_BUSID; i++) {
+		if (busid_table[i].name[0] &&
+		    busid_table[i].shutdown_busid) {
+			busid_priv = &(busid_table[i]);
+			busid_priv->status = STUB_BUSID_OTHER;
+		}
+	}
+	spin_unlock(&busid_table_lock);
+
+	/* now run rebind - no need to hold locks. driver files are removed */
+	for (i = 0; i < MAX_BUSID; i++) {
+		if (busid_table[i].name[0] &&
+		    busid_table[i].shutdown_busid) {
+			busid_priv = &(busid_table[i]);
+			do_rebind(busid_table[i].name, busid_priv);
+		}
+	}
+#endif
+}
+
 static ssize_t rebind_store(struct device_driver *dev, const char *buf,
 				 size_t count)
 {
@@ -186,16 +261,17 @@ static ssize_t rebind_store(struct device_driver *dev, const char *buf,
 	if (!bid)
 		return -ENODEV;
 
-	/* device_attach() callers should hold parent lock for USB */
-	if (bid->udev->dev.parent)
-		device_lock(bid->udev->dev.parent);
-	ret = device_attach(&bid->udev->dev);
-	if (bid->udev->dev.parent)
-		device_unlock(bid->udev->dev.parent);
-	if (ret < 0) {
-		dev_err(&bid->udev->dev, "rebind failed\n");
+	/* mark the device for deletion so probe ignores it during rescan */
+	bid->status = STUB_BUSID_OTHER;
+	/* release the busid lock */
+	put_busid_priv(bid);
+
+	ret = do_rebind((char *) buf, bid);
+	if (ret < 0)
 		return ret;
-	}
+
+	/* delete device from busid_table */
+	del_match_busid((char *) buf);
 
 	return count;
 }
@@ -317,6 +393,9 @@ static void __exit usbip_host_exit(void)
 	 */
 	usb_deregister_device_driver(&stub_driver);
 
+	/* initiate scan to attach devices */
+	stub_device_rebind();
+
 	kmem_cache_destroy(stub_priv_cache);
 }