Patch "usbip: prevent bind loops on devices attached to vhci_hcd" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

usbip: prevent bind loops on devices attached to vhci_hcd

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usbip-prevent-bind-loops-on-devices-attached-to-vhci_hcd.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Shuah Khan <[email protected]>
Date: Wed, 17 Jan 2018 12:07:30 -0700
Subject: usbip: prevent bind loops on devices attached to vhci_hcd

From: Shuah Khan <[email protected]>

commit ef54cf0c600fb8f5737fb001a9e357edda1a1de8 upstream.

usbip host binds to devices attached to vhci_hcd on the same server when user does attach over localhost or specifies the server as the remote.

usbip attach -r localhost -b busid
or
usbip attach -r servername (or server IP)

Unbind followed by bind works, however device is left in a bad state with accesses via the attached busid result in errors and system hangs during shutdown.

Fix it to check and bail out if the device is already attached to vhci_hcd.

---
 tools/usb/usbip/src/usbip_bind.c |    9 +++++++++
 1 file changed, 9 insertions(+)

@@ -144,6 +144,7 @@ static int bind_device(char *busid)
 	int rc;
 	struct udev *udev;
 	struct udev_device *dev;
+	const char *devpath;
 
 	/* Check whether the device with this bus ID exists. */
 	udev = udev_new();

@@ -152,8 +153,16 @@ static int bind_device(char *busid)
 		err("device with the specified bus ID does not exist");
 		return -1;
 	}
+	devpath = udev_device_get_devpath(dev);
 	udev_unref(udev);
 
+	/* If the device is already attached to vhci_hcd - bail out */
+	if (strstr(devpath, USBIP_VHCI_DRV_NAME)) {
+		err("bind loop detected: device: %s is attached to %s\n",
+		    devpath, USBIP_VHCI_DRV_NAME);
+		return -1;
+	}
+
 	rc = unbind_other(busid);
 	if (rc == UNBIND_ST_FAILED) {
 		err("could not unbind driver from device on busid %s", busid);

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/usbip-list-don-t-list-devices-attached-to-vhci_hcd.patch queue-4.14/usbip-prevent-bind-loops-on-devices-attached-to-vhci_hcd.patch queue-4.14/cpupowerutils-bench-fix-cpu-online-check.patch queue-4.14/cpupower-fix-cpupower-working-when-cpu0-is-offline.patch