WANG Cong 86e363dc3b net_sched: invoke ->attach() after setting dev->qdisc ... For mq qdisc, we add per tx queue qdisc to root qdisc for display purpose, however, that happens too early, before the new dev->qdisc is finally set, this causes q->list points to an old root qdisc which is going to be freed right before assigning with a new one. Fix this by moving ->attach() after setting dev->qdisc. For the record, this fixes the following crash: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 975 at lib/list_debug.c:59 __list_del_entry+0x5a/0x98() list_del corruption. prev->next should be ffff8800d1998ae8, but was 6b6b6b6b6b6b6b6b CPU: 1 PID: 975 Comm: tc Not tainted 4.1.0-rc4+ #1019 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000009 ffff8800d73fb928 ffffffff81a44e7f 0000000047574756 ffff8800d73fb978 ffff8800d73fb968 ffffffff810790da ffff8800cfc4cd20 ffffffff814e725b ffff8800d1998ae8 ffffffff82381250 0000000000000000 Call Trace: [<ffffffff81a44e7f>] dump_stack+0x4c/0x65 [<ffffffff810790da>] warn_slowpath_common+0x9c/0xb6 [<ffffffff814e725b>] ? __list_del_entry+0x5a/0x98 [<ffffffff81079162>] warn_slowpath_fmt+0x46/0x48 [<ffffffff81820eb0>] ? dev_graft_qdisc+0x5e/0x6a [<ffffffff814e725b>] __list_del_entry+0x5a/0x98 [<ffffffff814e72a7>] list_del+0xe/0x2d [<ffffffff81822f05>] qdisc_list_del+0x1e/0x20 [<ffffffff81820cd1>] qdisc_destroy+0x30/0xd6 [<ffffffff81822676>] qdisc_graft+0x11d/0x243 [<ffffffff818233c1>] tc_get_qdisc+0x1a6/0x1d4 [<ffffffff810b5eaf>] ? mark_lock+0x2e/0x226 [<ffffffff817ff8f5>] rtnetlink_rcv_msg+0x181/0x194 [<ffffffff817ff72e>] ? rtnl_lock+0x17/0x19 [<ffffffff817ff72e>] ? rtnl_lock+0x17/0x19 [<ffffffff817ff774>] ? __rtnl_unlock+0x17/0x17 [<ffffffff81855dc6>] netlink_rcv_skb+0x4d/0x93 [<ffffffff817ff756>] rtnetlink_rcv+0x26/0x2d [<ffffffff818544b2>] netlink_unicast+0xcb/0x150 [<ffffffff81161db9>] ? might_fault+0x59/0xa9 [<ffffffff81854f78>] netlink_sendmsg+0x4fa/0x51c [<ffffffff817d6e09>] sock_sendmsg_nosec+0x12/0x1d [<ffffffff817d8967>] sock_sendmsg+0x29/0x2e [<ffffffff817d8cf3>] ___sys_sendmsg+0x1b4/0x23a [<ffffffff8100a1b8>] ? native_sched_clock+0x35/0x37 [<ffffffff810a1d83>] ? sched_clock_local+0x12/0x72 [<ffffffff810a1fd4>] ? sched_clock_cpu+0x9e/0xb7 [<ffffffff810def2a>] ? current_kernel_time+0xe/0x32 [<ffffffff810b4bc5>] ? lock_release_holdtime.part.29+0x71/0x7f [<ffffffff810ddebf>] ? read_seqcount_begin.constprop.27+0x5f/0x76 [<ffffffff810b6292>] ? trace_hardirqs_on_caller+0x17d/0x199 [<ffffffff811b14d5>] ? __fget_light+0x50/0x78 [<ffffffff817d9808>] __sys_sendmsg+0x42/0x60 [<ffffffff817d9838>] SyS_sendmsg+0x12/0x1c [<ffffffff81a50e97>] system_call_fastpath+0x12/0x6f ---[ end trace ef29d3fb28e97ae7 ]--- For long term, we probably need to clean up the qdisc_graft() code in case it hides other bugs like this. Fixes: 95dc19299f ("pkt_sched: give visibility to mq slave qdiscs") Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-05-27 14:09:55 -04:00
..
act_api.c
act_bpf.c
act_connmark.c	net: sched: act_connmark: don't zap skb->nfct	2015-04-29 14:56:40 -04:00
act_csum.c
act_gact.c
act_ipt.c
act_mirred.c
act_nat.c
act_pedit.c
act_police.c
act_simple.c
act_skbedit.c
act_vlan.c
cls_api.c	net: sched: fix call_rcu() race on classifier module unloads	2015-05-21 18:48:18 -04:00
cls_basic.c
cls_bpf.c
cls_cgroup.c
cls_flow.c
cls_fw.c
cls_route.c
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h
cls_tcindex.c
cls_u32.c
em_canid.c
em_cmp.c
em_ipset.c
em_meta.c
em_nbyte.c
em_text.c
em_u32.c
ematch.c
Kconfig
Makefile
sch_api.c	net_sched: invoke ->attach() after setting dev->qdisc	2015-05-27 14:09:55 -04:00
sch_atm.c
sch_blackhole.c
sch_cbq.c
sch_choke.c
sch_codel.c	codel: fix maxpacket/mtu confusion	2015-05-03 22:17:40 -04:00
sch_drr.c
sch_dsmark.c
sch_fifo.c
sch_fq_codel.c	codel: fix maxpacket/mtu confusion	2015-05-03 22:17:40 -04:00
sch_fq.c
sch_generic.c
sch_gred.c	net_sched: gred: use correct backlog value in WRED mode	2015-05-11 13:26:26 -04:00
sch_hfsc.c
sch_hhf.c
sch_htb.c
sch_ingress.c
sch_mq.c
sch_mqprio.c
sch_multiq.c
sch_netem.c
sch_pie.c
sch_plug.c
sch_prio.c
sch_qfq.c
sch_red.c
sch_sfb.c
sch_sfq.c
sch_tbf.c
sch_teql.c