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

From: Gustavo A. R. Silva
Date: Fri Feb 16 2018 - 12:49:55 EST




On 02/16/2018 09:56 AM, Richard Cochran wrote:
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.

And so the real bug is the pointless range checking tests. I would
welcome patches to remove those.


I just sent a patch for this.

Thank you both, Andrew and Richard for the feedback.
--
Gustavo