Patch "usbip: fix stub_rx: get_pipe() to validate endpoint number" has been added to the 4.4-stable tree

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

usbip: fix stub_rx: get_pipe() to validate endpoint number

to the 4.4-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-fix-stub_rx-get_pipe-to-validate-endpoint-number.patch
and it can be found in the queue-4.4 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: Thu, 7 Dec 2017 14:16:47 -0700
Subject: usbip: fix stub_rx: get_pipe() to validate endpoint number

From: Shuah Khan <[email protected]>

commit 635f545a7e8be7596b9b2b6a43cab6bbd5a88e43 upstream.

get_pipe() routine doesn't validate the input endpoint number and uses to reference ep_in and ep_out arrays. Invalid endpoint number can trigger BUG(). Range check the epnum and returning error instead of calling BUG().

Change caller stub_recv_cmd_submit() to handle the get_pipe() error return.

---
 drivers/usb/usbip/stub_rx.c |   18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

@@ -344,15 +344,15 @@ static int get_pipe(struct stub_device *
 	struct usb_host_endpoint *ep;
 	struct usb_endpoint_descriptor *epd = NULL;
 
+	if (epnum < 0 || epnum > 15)
+		goto err_ret;
+
 	if (dir == USBIP_DIR_IN)
 		ep = udev->ep_in[epnum & 0x7f];
 	else
 		ep = udev->ep_out[epnum & 0x7f];
-	if (!ep) {
-		dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
-			epnum);
-		BUG();
-	}
+	if (!ep)
+		goto err_ret;
 
 	epd = &ep->desc;
 	if (usb_endpoint_xfer_control(epd)) {

@@ -383,9 +383,10 @@ static int get_pipe(struct stub_device *
 			return usb_rcvisocpipe(udev, epnum);
 	}
 
+err_ret:
 	/* NOT REACHED */
-	dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
-	return 0;
+	dev_err(&sdev->udev->dev, "get pipe() invalid epnum %d\n", epnum);
+	return -1;
 }
 
 static void masking_bogus_flags(struct urb *urb)

@@ -451,6 +452,9 @@ static void stub_recv_cmd_submit(struct
 	struct usb_device *udev = sdev->udev;
 	int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 
+	if (pipe == -1)
+		return;
+
 	priv = stub_priv_alloc(sdev, pdu);
 	if (!priv)
 		return;

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

queue-4.4/usbip-fix-stub_rx-harden-cmd_submit-path-to-handle-malicious-input.patch queue-4.4/usbip-fix-potential-format-overflow-in-userspace-tools.patch queue-4.4/usbip-fix-implicit-fallthrough-warning.patch queue-4.4/usbip-prevent-leaking-socket-pointer-address-in-messages.patch queue-4.4/usbip-fix-stub_rx-get_pipe-to-validate-endpoint-number.patch queue-4.4/usbip-prevent-vhci_hcd-driver-from-leaking-a-socket-pointer-address.patch queue-4.4/usb-usbip-fix-possible-deadlocks-reported-by-lockdep.patch