4.4-stable review patch. If anyone has any objections, please let me know.
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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 | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-)
--- a/drivers/usb/usbip/stub_rx.c +++ b/drivers/usb/usbip/stub_rx.c @@ -338,11 +338,13 @@ 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; @@ -355,6 +357,7 @@ static int get_pipe(struct stub_device * goto err_ret;
epd = &ep->desc; + if (usb_endpoint_xfer_control(epd)) { if (dir == USBIP_DIR_OUT) return usb_sndctrlpipe(udev, epnum); @@ -377,6 +380,27 @@ 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; + +#define USB_EP_MAXP_MULT_SHIFT 11 +#define USB_EP_MAXP_MULT_MASK (3 << USB_EP_MAXP_MULT_SHIFT) +#define USB_EP_MAXP_MULT(m) \ + (((m) & USB_EP_MAXP_MULT_MASK) >> USB_EP_MAXP_MULT_SHIFT) + + maxp = usb_endpoint_maxp(epd); + maxp *= (USB_EP_MAXP_MULT( + __le16_to_cpu(epd->wMaxPacketSize)) + 1); + 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 @@ -385,7 +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; }
@@ -450,7 +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;