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 my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
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
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 Cc: stable stable@vger.kernel.org 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(-)
diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c index 4d61063c259d..493ac2928391 100644 --- a/drivers/usb/usbip/stub_rx.c +++ b/drivers/usb/usbip/stub_rx.c @@ -322,11 +322,13 @@ static struct stub_priv *stub_priv_alloc(struct stub_device *sdev, 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; @@ -339,6 +341,15 @@ static int get_pipe(struct stub_device *sdev, int epnum, int dir) 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); @@ -361,6 +372,21 @@ static int get_pipe(struct stub_device *sdev, int epnum, int dir) }
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 @@ -369,7 +395,7 @@ static int get_pipe(struct stub_device *sdev, int epnum, int dir)
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; }
@@ -434,7 +460,7 @@ static void stub_recv_cmd_submit(struct stub_device *sdev, 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; @@ -456,7 +482,8 @@ static void stub_recv_cmd_submit(struct stub_device *sdev, }
/* 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);