Oliver Neukum <oneukum@xxxxxxxx> writes:
> CDC-NCM: avoid overflow in sanity checking A broken device may give an
> extreme offset like 0xFFF0 and a reasonable length for a fragment. In
> the sanity check as formulated now, this will create an integer
> overflow, defeating the sanity check. It needs to be rewritten as a
> subtraction and the variables should be unsigned. Signed-off-by: Oliver
> Neukum <oneukum@xxxxxxxx> --- drivers/net/usb/cdc_ncm.c | 6 +++--- 1
> file changed, 3 insertions(+), 3 deletions(-) diff --git
> a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index
> e303b522efb5..f78fccbc4b93 100644 --- a/drivers/net/usb/cdc_ncm.c +++
> b/drivers/net/usb/cdc_ncm.c @@ -1715,10 +1715,10 @@ 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; + unsigned int len; int nframes; int x; - int
> offset; + unsigned int offset; union { struct usb_cdc_ncm_ndp16 *ndp16;
> struct usb_cdc_ncm_ndp32 *ndp32; @@ -1791,7 +1791,7 @@ int
> cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in) } /* sanity
> checking */ - if (((offset + len) > skb_in->len) || + if ((offset >
> skb_in->len - len) || (len > ctx->rx_max) || (len < ETH_HLEN)) {
> netif_dbg(dev, rx_err, dev->net, "invalid frame detected (ignored)
> offset[%u]=%u, length=%u, skb=%p\n", -- 2.34.1
I don't mind taking a look at it, but that's beyond unreadable...
Could you please resend using "git send-email" or something else that
works?
Bjørn
