diff options
| -rw-r--r-- | drivers/net/usb/cdc_ncm.c | 83 |
1 files changed, 55 insertions, 28 deletions
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 34069346544f..6688a15e044d 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -966,19 +966,12 @@ error: return NULL; } -static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in) +/* verify NTB header and return offset of first NDP, or negative error */ +static int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in) { - struct sk_buff *skb; - struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; - int len; - int nframes; - int x; - int offset; struct usb_cdc_ncm_nth16 *nth16; - struct usb_cdc_ncm_ndp16 *ndp16; - struct usb_cdc_ncm_dpe16 *dpe16; - int ndpoffset; - int loopcount = 50; /* arbitrary max preventing infinite loop */ + int len; + int ret = -EINVAL; if (ctx == NULL) goto error; @@ -1012,40 +1005,74 @@ static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in) } ctx->rx_seq = le16_to_cpu(nth16->wSequence); - ndpoffset = le16_to_cpu(nth16->wNdpIndex); -next_ndp: + ret = le16_to_cpu(nth16->wNdpIndex); +error: + return ret; +} + +/* verify NDP header and return number of datagrams, or negative error */ +static int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset) +{ + struct usb_cdc_ncm_ndp16 *ndp16; + int ret = -EINVAL; + if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) { pr_debug("invalid NDP offset <%u>\n", ndpoffset); goto error; } ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset); - if (le32_to_cpu(ndp16->dwSignature) != USB_CDC_NCM_NDP16_NOCRC_SIGN) { - pr_debug("invalid DPT16 signature <%u>\n", - le32_to_cpu(ndp16->dwSignature)); - goto err_ndp; - } - if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) { pr_debug("invalid DPT16 length <%u>\n", le32_to_cpu(ndp16->dwSignature)); - goto err_ndp; + goto error; } - nframes = ((le16_to_cpu(ndp16->wLength) - + ret = ((le16_to_cpu(ndp16->wLength) - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16)); - nframes--; /* we process NDP entries except for the last one */ - - ndpoffset += sizeof(struct usb_cdc_ncm_ndp16); + ret--; /* we process NDP entries except for the last one */ - if ((ndpoffset + nframes * (sizeof(struct usb_cdc_ncm_dpe16))) > + if ((sizeof(struct usb_cdc_ncm_ndp16) + ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) { - pr_debug("Invalid nframes = %d\n", nframes); - goto err_ndp; + pr_debug("Invalid nframes = %d\n", ret); + ret = -EINVAL; } - dpe16 = (struct usb_cdc_ncm_dpe16 *)(skb_in->data + ndpoffset); +error: + return ret; +} + +static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in) +{ + struct sk_buff *skb; + struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; + int len; + int nframes; + int x; + int offset; + struct usb_cdc_ncm_ndp16 *ndp16; + struct usb_cdc_ncm_dpe16 *dpe16; + int ndpoffset; + int loopcount = 50; /* arbitrary max preventing infinite loop */ + + ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in); + if (ndpoffset < 0) + goto error; + +next_ndp: + nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset); + if (nframes < 0) + goto error; + + ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset); + + if (le32_to_cpu(ndp16->dwSignature) != USB_CDC_NCM_NDP16_NOCRC_SIGN) { + pr_debug("invalid DPT16 signature <%u>\n", + le32_to_cpu(ndp16->dwSignature)); + goto err_ndp; + } + dpe16 = ndp16->dpe16; for (x = 0; x < nframes; x++, dpe16++) { offset = le16_to_cpu(dpe16->wDatagramIndex); |
