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

usbip: fix stub_rx: harden CMD_SUBMIT path to handle malicious input

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: usbip-fix-stub_rx-harden-cmd_submit-path-to-handle-malicious-input.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From c6688ef9f29762e65bce325ef4acd6c675806366 Mon Sep 17 00:00:00 2001

From: Shuah Khan shuahkh@osg.samsung.com Date: Thu, 7 Dec 2017 14:16:48 -0700 Subject: usbip: fix stub_rx: harden CMD_SUBMIT path to handle malicious input

From: Shuah Khan shuahkh@osg.samsung.com

commit c6688ef9f29762e65bce325ef4acd6c675806366 upstream.

Harden CMD_SUBMIT path to handle malicious input that could trigger large memory allocations. Add checks to validate transfer_buffer_length and number_of_packets to protect against bad input requesting for unbounded memory allocations. Validate early in get_pipe() and return failure.

Reported-by: Secunia Research vuln@secunia.com Signed-off-by: Shuah Khan shuahkh@osg.samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/usb/usbip/stub_rx.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-)

--- a/drivers/usb/usbip/stub_rx.c +++ b/drivers/usb/usbip/stub_rx.c @@ -336,11 +336,13 @@ static struct stub_priv *stub_priv_alloc return priv; }

-static int get_pipe(struct stub_device *sdev, int epnum, int dir) +static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu) { struct usb_device *udev = sdev->udev; struct usb_host_endpoint *ep; struct usb_endpoint_descriptor *epd = NULL; + int epnum = pdu->base.ep; + int dir = pdu->base.direction;

if (epnum < 0 || epnum > 15) goto err_ret; @@ -353,6 +355,15 @@ static int get_pipe(struct stub_device * goto err_ret;

epd = &ep->desc; + + /* validate transfer_buffer_length */ + if (pdu->u.cmd_submit.transfer_buffer_length > INT_MAX) { + dev_err(&sdev->udev->dev, + "CMD_SUBMIT: -EMSGSIZE transfer_buffer_length %d\n", + pdu->u.cmd_submit.transfer_buffer_length); + return -1; + } + if (usb_endpoint_xfer_control(epd)) { if (dir == USBIP_DIR_OUT) return usb_sndctrlpipe(udev, epnum); @@ -375,6 +386,21 @@ static int get_pipe(struct stub_device * }

if (usb_endpoint_xfer_isoc(epd)) { + /* validate packet size and number of packets */ + unsigned int maxp, packets, bytes; + + maxp = usb_endpoint_maxp(epd); + maxp *= usb_endpoint_maxp_mult(epd); + bytes = pdu->u.cmd_submit.transfer_buffer_length; + packets = DIV_ROUND_UP(bytes, maxp); + + if (pdu->u.cmd_submit.number_of_packets < 0 || + pdu->u.cmd_submit.number_of_packets > packets) { + dev_err(&sdev->udev->dev, + "CMD_SUBMIT: isoc invalid num packets %d\n", + pdu->u.cmd_submit.number_of_packets); + return -1; + } if (dir == USBIP_DIR_OUT) return usb_sndisocpipe(udev, epnum); else @@ -383,7 +409,7 @@ static int get_pipe(struct stub_device *

err_ret: /* NOT REACHED */ - dev_err(&sdev->udev->dev, "get pipe() invalid epnum %d\n", epnum); + dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum); return -1; }

@@ -448,7 +474,7 @@ static void stub_recv_cmd_submit(struct struct stub_priv *priv; struct usbip_device *ud = &sdev->ud; struct usb_device *udev = sdev->udev; - int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction); + int pipe = get_pipe(sdev, pdu);

if (pipe == -1) return; @@ -470,7 +496,8 @@ static void stub_recv_cmd_submit(struct }

/* allocate urb transfer buffer, if needed */ - if (pdu->u.cmd_submit.transfer_buffer_length > 0) { + if (pdu->u.cmd_submit.transfer_buffer_length > 0 && + pdu->u.cmd_submit.transfer_buffer_length <= INT_MAX) { priv->urb->transfer_buffer = kzalloc(pdu->u.cmd_submit.transfer_buffer_length, GFP_KERNEL);

Patches currently in stable-queue which might be from shuahkh@osg.samsung.com are

queue-4.9/usbip-fix-stub_rx-harden-cmd_submit-path-to-handle-malicious-input.patch queue-4.9/usbip-fix-stub_send_ret_submit-vulnerability-to-null-transfer_buffer.patch queue-4.9/usbip-fix-stub_rx-get_pipe-to-validate-endpoint-number.patch