From 635f545a7e8be7596b9b2b6a43cab6bbd5a88e43 Mon Sep 17 00:00:00 2001
From: Shuah Khan <shuahkh@osg.samsung.com>
Date: Thu, 7 Dec 2017 14:16:47 -0700
Subject: [PATCH] usbip: fix stub_rx: get_pipe() to validate endpoint number
References: bsc#1078673 CVE-2017-16912
Git-commit: 635f545a7e8be7596b9b2b6a43cab6bbd5a88e43
Patch-mainline: v4.15-rc4
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.
Reported-by: Secunia Research <vuln@secunia.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/usbip/stub_rx.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
--- a/drivers/usb/usbip/stub_rx.c
+++ b/drivers/usb/usbip/stub_rx.c
@@ -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->udev->dev, "no such endpoint?, %d\n",
- epnum);
- BUG();
- }
+ if (!ep)
+ goto err_ret;
epd = &ep->desc;
if (usb_endpoint_xfer_control(epd)) {
@@ -407,8 +407,9 @@ static int get_pipe(struct stub_device *
return usb_rcvisocpipe(udev, epnum);
}
+err_ret:
/* NOT REACHED */
- dev_err(&sdev->udev->dev, "get pipe, epnum %d\n", epnum);
+ dev_err(&sdev->udev->dev, "get pipe() invalid epnum %d\n", epnum);
return 0;
}
@@ -475,6 +476,9 @@ 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;