netdev - [BUG] net/sched : qlen can not really be per cpu ?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <5fb87db3-d5bd-714b-213d-6821f4bf37da@gmail.com>
Date:   Mon, 25 Feb 2019 22:42:17 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     John Fastabend <john.fastabend@...il.com>,
        Networking <netdev@...r.kernel.org>,
        Jamal Hadi Salim <jhs@...atatu.com>,
        Cong Wang <xiyou.wangcong@...il.com>,
        Jiri Pirko <jiri@...nulli.us>
Subject: [BUG] net/sched : qlen can not really be per cpu ?

HTB + pfifo_fast as a leaf qdisc hits badly the following warning in htb_activate() :

WARN_ON(cl->level || !cl->leaf.q || !cl->leaf.q->q.qlen);

This is because pfifo_fast does not update sch->q.qlen, but per cpu counters.
So cl->leaf.q->q.qlen is zero.

HFSC, CBQ, DRR, QFQ  have the same problem.

Any ideas how we can fix this ?

Thanks !