Re: [PATCH] net: cgroup: fix out of bounds accesses

On Mon, Jul 09, 2012 at 09:45:10AM +0200, Eric Dumazet wrote:

From: Eric Dumazet <edumazet@google.com>

dev->priomap is allocated by extend_netdev_table() called from
update_netdev_tables().
And this is only called if write_priomap() is called.

But if write_priomap() is not called, it seems we can have out of bounds
accesses in cgrp_destroy(), read_priomap() & skb_update_prio()

With help from Gao Feng

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Gao feng <redacted>
---
net/core/dev.c            |    8 ++++++--
net/core/netprio_cgroup.c |    4 ++--
2 files changed, 8 insertions(+), 4 deletions(-)

Thank you for doing this Eric, Gao.  Just to be sure (I asked in the previous
thread), would it be better to avoid the length check in skb_update_prio, and
instead update the netdev tables to be long enough in cgrp_create and in
netprio_device_event on device registration?

Neil