On Mon, Jun 28, 2010 at 11:38 PM, Rajkumar Manoharan <rmanoharan@xxxxxxxxxxx> wrote: > get stats netdev ops is blindy called for older kernels (< 2.6.29) and > so assigning a NULL pointer from netdev_attach_ops causes a NULL pointer > dereference. > > By default, netdev alloc provides an internal stats reference. So fill > this only if ndo_get_stats is defined. > > Signed-off-by: Rajkumar Manoharan <rmanoharan@xxxxxxxxxxx> > --- > compat/compat-2.6.29.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/compat/compat-2.6.29.c b/compat/compat-2.6.29.c > index f94aed8..2e7e623 100644 > --- a/compat/compat-2.6.29.c > +++ b/compat/compat-2.6.29.c > @@ -35,7 +35,8 @@ void netdev_attach_ops(struct net_device *dev, > dev->change_mtu = ops->ndo_change_mtu; > dev->set_mac_address = ops->ndo_set_mac_address; > dev->tx_timeout = ops->ndo_tx_timeout; > - dev->get_stats = ops->ndo_get_stats; > + if (ops->ndo_get_stats) > + dev->get_stats = ops->ndo_get_stats; If ops->ndo_get_stats is NULL then dev->get_stats will be set to NULL. Do you know for sure this fixes something? If so can you explain how? I used to have a macro that checked for not NULL and if true set the callback but then later realized after Johannes poked me that this is silly given that if the op is NULL you are just setting it to NULL. I don't see the potential crash here. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
