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

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.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Shuah Khan 2017-12-22 19:23:46 -07:00 committed by Greg Kroah-Hartman
parent 30a7acd573
commit b78d830f00

View file

@ -120,6 +120,25 @@ static int v_recv_cmd_submit(struct vudc *udc,
urb_p->new = 1;
urb_p->seqnum = pdu->base.seqnum;
if (urb_p->ep->type == USB_ENDPOINT_XFER_ISOC) {
/* validate packet size and number of packets */
unsigned int maxp, packets, bytes;
maxp = usb_endpoint_maxp(urb_p->ep->desc);
maxp *= usb_endpoint_maxp_mult(urb_p->ep->desc);
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(&udc->gadget.dev,
"CMD_SUBMIT: isoc invalid num packets %d\n",
pdu->u.cmd_submit.number_of_packets);
ret = -EMSGSIZE;
goto free_urbp;
}
}
ret = alloc_urb_from_cmd(&urb_p->urb, pdu, urb_p->ep->type);
if (ret) {
usbip_event_add(&udc->ud, VUDC_EVENT_ERROR_MALLOC);