linux/net/sched
Maxim Mikityanskiy de2d807b29 sch_api: Don't skip qdisc attach on ingress
The attach callback of struct Qdisc_ops is used by only a few qdiscs:
mq, mqprio and htb. qdisc_graft() contains the following logic
(pseudocode):

    if (!qdisc->ops->attach) {
        if (ingress)
            do ingress stuff;
        else
            do egress stuff;
    }
    if (!ingress) {
        ...
        if (qdisc->ops->attach)
            qdisc->ops->attach(qdisc);
    } else {
        ...
    }

As we see, the attach callback is not called if the qdisc is being
attached to ingress (TC_H_INGRESS). That wasn't a problem for mq and
mqprio, since they contain a check that they are attached to TC_H_ROOT,
and they can't be attached to TC_H_INGRESS anyway.

However, the commit cited below added the attach callback to htb. It is
needed for the hardware offload, but in the non-offload mode it
simulates the "do egress stuff" part of the pseudocode above. The
problem is that when htb is attached to ingress, neither "do ingress
stuff" nor attach() is called. It results in an inconsistency, and the
following message is printed to dmesg:

unregister_netdevice: waiting for lo to become free. Usage count = 2

This commit addresses the issue by running "do ingress stuff" in the
ingress flow even in the attach callback is present, which is fine,
because attach isn't going to be called afterwards.

The bug was found by syzbot and reported by Eric.

Fixes: d03b195b5a ("sch_htb: Hierarchical QoS hardware offload")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-13 12:34:59 +00:00
..
act_api.c flow_offload: fix suspicious RCU usage when offloading tc action 2021-12-23 11:17:00 +00:00
act_bpf.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_connmark.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_csum.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_ct.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-09 17:00:17 -08:00
act_ctinfo.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_gact.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_gate.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_ife.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_ipt.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_mpls.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_nat.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_pedit.c flow_offload: add ops to tc_action_ops for flow action setup 2021-12-19 14:08:48 +00:00
act_police.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_sample.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_simple.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_skbedit.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_skbmod.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_tunnel_key.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_vlan.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
cls_api.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-09 17:00:17 -08:00
cls_basic.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_bpf.c bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
cls_cgroup.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flow.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flower.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-23 16:09:58 -08:00
cls_fw.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_matchall.c flow_offload: validate flags of filter and actions 2021-12-19 14:08:48 +00:00
cls_route.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_tcindex.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_u32.c flow_offload: validate flags of filter and actions 2021-12-19 14:08:48 +00:00
em_canid.c net: sched: kerneldoc fixes 2020-07-13 17:20:40 -07:00
em_cmp.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
em_ipset.c sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
em_ipt.c sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
em_meta.c net: introduce sk_forward_alloc_get() 2021-10-27 18:20:29 -07:00
em_nbyte.c net: sched: Return the correct errno code 2021-02-06 11:15:28 -08:00
em_text.c
em_u32.c
ematch.c net: sched: Fix spelling mistakes 2021-05-31 22:44:56 -07:00
Kconfig net: sched: incorrect Kconfig dependencies on Netfilter modules 2020-12-09 15:49:29 -08:00
Makefile net/sched: sch_frag: add generic packet fragment support. 2020-11-27 14:36:02 -08:00
sch_api.c sch_api: Don't skip qdisc attach on ingress 2022-01-13 12:34:59 +00:00
sch_atm.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_blackhole.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_cake.c sch_cake: revise Diffserv docs 2022-01-07 08:41:29 -08:00
sch_cbq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_cbs.c net: don't include ethtool.h from netdevice.h 2020-11-23 17:27:04 -08:00
sch_choke.c net: sched: validate stab values 2021-03-10 15:47:52 -08:00
sch_codel.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_drr.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_dsmark.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_etf.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_ets.c net/sched: sch_ets: don't remove idle classes from the round-robin list 2021-12-13 12:30:23 +00:00
sch_fifo.c net_sched: fix NULL deref in fifo_set_limit() 2021-10-01 14:59:10 -07:00
sch_fq_codel.c fq_codel: generalise ce_threshold marking for subset of traffic 2021-10-20 15:24:36 -07:00
sch_fq_pie.c net/sched: fq_pie: prevent dismantle issue 2021-12-09 08:01:00 -08:00
sch_fq.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_frag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
sch_generic.c net: watchdog: add net device refcount tracker 2021-12-07 20:44:58 -08:00
sch_gred.c net: sched: gred: dynamically allocate tc_gred_qopt_offload 2021-10-27 12:06:52 -07:00
sch_hfsc.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_hhf.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_htb.c sch_htb: Add extack messages for EOPNOTSUPP errors 2021-10-28 14:34:03 +01:00
sch_ingress.c net: sched: Pass ingress block to tcf_classify_ingress 2020-02-19 17:49:48 -08:00
sch_mq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_mqprio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_multiq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_netem.c net: sched: sch_netem: Refactor code in 4-state loss generator 2021-11-15 13:23:23 +00:00
sch_pie.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
sch_plug.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_prio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_qfq.c sch_qfq: prevent shift-out-of-bounds in qfq_init_qdisc 2022-01-04 12:36:51 +00:00
sch_red.c net: sched: validate stab values 2021-03-10 15:47:52 -08:00
sch_sfb.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_sfq.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_skbprio.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_taprio.c net/sched: sch_taprio: fix undefined behavior in ktime_mono_to_any 2021-11-09 19:16:23 -08:00
sch_tbf.c net: sch_tbf: Add a graft command 2021-10-19 12:24:51 +01:00
sch_teql.c net: sched: sch_teql: fix null-pointer dereference 2021-04-08 14:14:42 -07:00