On Wed, Nov 23, 2011 at 09:22:16AM +0100, walter harms wrote:

I am not sure that it does what you intends.
mnemonic is an array and a  malicious use may fill it upto the last char
causing strlen go beyond. perhaps this may help:

Correct, it makes thigs worse.  I'm going to reply in detail later tonight,
have to bail out now.

quoted

 		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
 			return -EINVAL;

while you are here:

	dev = nr_ax25_dev_get(nr_route.device);
	if ( dev == NULL )
		return -EINVAL;

quoted

 		if (nr_route.ndigis < 0 || nr_route.ndigis > AX25_MAX_DIGIS) {

if guess "nr_route.ndigis >= AX25_MAX_DIGIS" is intended ?

No, values of 0 .. AX25_MAX_DIGIS are permitted with zero meaning no
digipeater at all.

The actual bug if you want to call it that in this line is cosmetic -
nr_route.ndigis is an unsigned int so nr_route.ndigis < 0 will never become
true.  There are other simplifications possible to the error checking
here.  I've whipped a cleanup patch for this part of the code.

  Ralf