HI!
> From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> [ Upstream commit a6921dd524fe31d1f460c161d3526a407533b6db ]
>
> These values come from skb->data so Smatch considers them untrusted. I
> believe Smatch is correct but I don't have a way to test this.
>
> The usb_if->dev[] array has 2 elements but the index is in the 0-15
> range without checks. The cfd->len can be up to 255 but the maximum
> valid size is CANFD_MAX_DLEN (64) so that could lead to memory
> corruption.
If this is untrusted, does it need to use _nospec() variants?
> index 41988358f63c8..19600d35aac55 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> @@ -476,12 +476,18 @@ static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if,
> struct pucan_msg *rx_msg)
> {
...
> const u16 rx_msg_flags = le16_to_cpu(rm->flags);
>
> + if (pucan_msg_get_channel(rm) >= ARRAY_SIZE(usb_if->dev))
> + return -ENOMEM;
Furthermore, should it use -EINVAL here
> + if (pucan_stmsg_get_channel(sm) >= ARRAY_SIZE(usb_if->dev))
> + return -ENOMEM;
and here, and perhaps use a helper function?
Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek
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