4.9-stable review patch. If anyone has any objections, please let me know.
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From: Shuah Khan shuahkh@osg.samsung.com
commit b78d830f0049ef1966dc1e0ebd1ec2a594e2cf25 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.
Signed-off-by: Shuah Khan shuahkh@osg.samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/usbip/vudc_rx.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
--- a/drivers/usb/usbip/vudc_rx.c +++ b/drivers/usb/usbip/vudc_rx.c @@ -132,6 +132,25 @@ static int v_recv_cmd_submit(struct vudc 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);