From: Shuah Khan <shuahkh@osg.samsung.com>
Date: Thu, 5 Apr 2018 22:29:04 +0000 (-0600)
Subject: usbip: usbip_host: fix to hold parent lock for device_attach() calls
X-Git-Tag: v4.1.52~56
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dff14704cd1b0cc3b5ba1384c1b3101edd05f810;p=thirdparty%2Fkernel%2Fstable.git

usbip: usbip_host: fix to hold parent lock for device_attach() calls

[ Upstream commit 4bfb141bc01312a817d36627cc47c93f801c216d ]

usbip_host calls device_attach() without holding dev->parent lock.
Fix it.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---

diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c
index 325b4c05acdd3..f761e02e75c9c 100644
--- a/drivers/usb/usbip/stub_main.c
+++ b/drivers/usb/usbip/stub_main.c
@@ -201,7 +201,12 @@ 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");
 		return ret;