| Message ID | 1604373938-211588-1-git-send-email-linyunsheng@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [stable] net: sch_generic: fix the missing new qdisc assignment bug | expand |
On Tue, Nov 03, 2020 at 11:25:38AM +0800, Yunsheng Lin wrote: > commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") > > When the above upstream commit is backported to stable kernel, > one assignment is missing, which causes two problems reported > by Joakim and Vishwanath, see [1] and [2]. > > So add the assignment back to fix it. > > 1. https://www.spinics.net/lists/netdev/msg693916.html > 2. https://www.spinics.net/lists/netdev/msg695131.html > > Fixes: 749cc0b0c7f3 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") > Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> > --- > net/sched/sch_generic.c | 3 +++ > 1 file changed, 3 insertions(+) What kernel tree(s) does this need to be backported to? thanks, greg k-h
On Tue, Nov 03, 2020 at 11:25:38AM +0800, Yunsheng Lin wrote: > commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") > > When the above upstream commit is backported to stable kernel, > one assignment is missing, which causes two problems reported > by Joakim and Vishwanath, see [1] and [2]. > > So add the assignment back to fix it. > > 1. https://www.spinics.net/lists/netdev/msg693916.html > 2. https://www.spinics.net/lists/netdev/msg695131.html > > Fixes: 749cc0b0c7f3 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") > Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> For whatever it's worth, we've seen similar problems (particularly, ENOBUFS on AF_PACKET sockets) and have tested this fix on 4.19.y (we're also queueing it up on our 5.4.y branch, but haven't tested it as much): Tested-by: Brian Norris <briannorris@chromium.org> Thanks!
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 0e275e1..6e6147a 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1127,10 +1127,13 @@ static void dev_deactivate_queue(struct net_device *dev, void *_qdisc_default) { struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc); + struct Qdisc *qdisc_default = _qdisc_default; if (qdisc) { if (!(qdisc->flags & TCQ_F_BUILTIN)) set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); + + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); } }
commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") When the above upstream commit is backported to stable kernel, one assignment is missing, which causes two problems reported by Joakim and Vishwanath, see [1] and [2]. So add the assignment back to fix it. 1. https://www.spinics.net/lists/netdev/msg693916.html 2. https://www.spinics.net/lists/netdev/msg695131.html Fixes: 749cc0b0c7f3 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> --- net/sched/sch_generic.c | 3 +++ 1 file changed, 3 insertions(+)