Commit 3ea3091f authored by Shuah Khan's avatar Shuah Khan Committed by Greg Kroah-Hartman
Browse files

usbip: usbip_host: fix stub_dev lock context imbalance regression 

Fix the following sparse context imbalance regression introduced in
a patch that fixed sleeping function called from invalid context bug.

kbuild test robot reported on:

tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git

  usb-linus

Regressions in current branch:

drivers/usb/usbip/stub_dev.c:399:9: sparse: sparse: context imbalance in 'stub_probe' - different lock contexts for basic block
drivers/usb/usbip/stub_dev.c:418:13: sparse: sparse: context imbalance in 'stub_disconnect' - different lock contexts for basic block
drivers/usb/usbip/stub_dev.c:464:1-10: second lock on line 476

Error ids grouped by kconfigs:

recent_errors
├── i386-allmodconfig
│   └── drivers-usb-usbip-stub_dev.c:second-lock-on-line
├── x86_64-allmodconfig
│   ├── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_disconnect-different-lock-contexts-for-basic-block
│   └── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_probe-different-lock-contexts-for-basic-block
└── x86_64-allyesconfig
    └── drivers-usb-usbip-stub_dev.c:second-lock-on-line

This is a real problem in an error leg where spin_lock() is called on an
already held lock.

Fix the imbalance in stub_probe() and stub_disconnect().

Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Fixes: 0c9e8b3c ("usbip: usbip_host: fix BUG: sleeping function called from invalid context")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a4768663

drivers/usb/usbip/stub_dev.c

+23 −13
Original line number Diff line number Diff line
@@ -326,14 +326,17 @@ static int stub_probe(struct usb_device *udev) 
		 * See driver_probe_device() in driver/base/dd.c

		 */

		rc = -ENODEV;

		if (!busid_priv)

			goto sdev_free;



		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);

		rc = -ENODEV;

		goto sdev_free;

		goto call_put_busid_priv;

	}



	if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
@@ -342,7 +345,7 @@ static int stub_probe(struct usb_device *udev) 
			udev_busid);



		rc = -ENODEV;

		goto sdev_free;

		goto call_put_busid_priv;

	}
@@ -361,6 +364,9 @@ static int stub_probe(struct usb_device *udev) 
	save_status = busid_priv->status;

	busid_priv->status = STUB_BUSID_ALLOC;



	/* release the busid_lock */

	put_busid_priv(busid_priv);



	/*

	 * Claim this hub port.

	 * It doesn't matter what value we pass as owner
@@ -373,9 +379,6 @@ static int stub_probe(struct usb_device *udev) 
		goto err_port;

	}



	/* release the busid_lock */

	put_busid_priv(busid_priv);



	rc = stub_add_files(&udev->dev);

	if (rc) {

		dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid);
@@ -395,11 +398,17 @@ err_port: 
	spin_lock(&busid_priv->busid_lock);

	busid_priv->sdev = NULL;

	busid_priv->status = save_status;

sdev_free:

	stub_device_free(sdev);

	spin_unlock(&busid_priv->busid_lock);

	/* lock is released - go to free */

	goto sdev_free;



call_put_busid_priv:

	/* release the busid_lock */

	put_busid_priv(busid_priv);



sdev_free:

	stub_device_free(sdev);



	return rc;

}
@@ -435,7 +444,9 @@ static void stub_disconnect(struct usb_device *udev) 
	/* get stub_device */

	if (!sdev) {

		dev_err(&udev->dev, "could not get device");

		goto call_put_busid_priv;

		/* release busid_lock */

		put_busid_priv(busid_priv);

		return;

	}



	dev_set_drvdata(&udev->dev, NULL);
@@ -465,7 +476,7 @@ static void stub_disconnect(struct usb_device *udev) 
	if (!busid_priv->shutdown_busid)

		busid_priv->shutdown_busid = 1;

	/* release busid_lock */

	put_busid_priv(busid_priv);

	spin_unlock(&busid_priv->busid_lock);



	/* shutdown the current connection */

	shutdown_busid(busid_priv);
@@ -480,10 +491,9 @@ static void stub_disconnect(struct usb_device *udev) 


	if (busid_priv->status == STUB_BUSID_ALLOC)

		busid_priv->status = STUB_BUSID_ADDED;



call_put_busid_priv:

	/* release busid_lock */

	put_busid_priv(busid_priv);

	spin_unlock(&busid_priv->busid_lock);

	return;

}



#ifdef CONFIG_PM

CRA Git | Maintained and supported by SUSTech CRA and CCSE