On Tue, 4 Apr 2017, Cong Wang wrote:
> Dmitry reported a crash when injecting faults in
> attach_one_default_qdisc() and dev->qdisc is still
> a noop_disc, the check before qdisc_hash_add() fails
> to catch it because it tests NULL. We should test
> against noop_qdisc since it is the default qdisc
> at this point.
>
> Fixes: 59cc1f61f09c ("net: sched: convert qdisc linked list to hashtable")
> Reported-by: Dmitry Vyukov <dvyu...@google.com>
> Cc: Jiri Kosina <jkos...@suse.cz>
> Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
Acked-by: Jiri Kosina <jkos...@suse.cz>
Thanks.
> ---
> net/sched/sch_generic.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
> index b052b27..1a2f9e9 100644
> --- a/net/sched/sch_generic.c
> +++ b/net/sched/sch_generic.c
> @@ -794,7 +794,7 @@ static void attach_default_qdiscs(struct net_device *dev)
> }
> }
> #ifdef CONFIG_NET_SCHED
> - if (dev->qdisc)
> + if (dev->qdisc != &noop_qdisc)
> qdisc_hash_add(dev->qdisc);
> #endif
> }
> --
> 2.5.5
>
--
Jiri Kosina
SUSE Labs
