Re: [PATCH v2] net: dsa: mv88e6xxx: hwtstamp: fix potential negative array index read

Andrew Lunn
2018-02-16T15:55:54Z

On Fri, Feb 16, 2018 at 07:48:46AM -0800, Richard Cochran wrote:
> On Thu, Feb 15, 2018 at 12:31:39PM -0600, Gustavo A. R. Silva wrote:
> > _port_ is being used as index to array port_hwtstamp before verifying
> > it is a non-negative number and a valid index at line 209 and 258:
> >
> > if (port < 0 || port >= mv88e6xxx_num_ports(chip))
> >
> > Fix this by checking _port_ before using it as index to array
> > port_hwtstamp.
>
> NAK. Port is already known to be valid in the callers.

Then we should take out the check. It is probably this check which is
causing the false positives.

Andrew