netdev - [PATCH/RFC net-next v2 0/4] net/sched: cls_flower: avoid false matching of truncated packets

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]

Date:   Fri,  5 May 2017 14:47:02 +0200
From:   Simon Horman <simon.horman@...ronome.com>
To:     Jiri Pirko <jiri@...lanox.com>,
        Jamal Hadi Salim <jhs@...atatu.com>,
        Cong Wang <xiyou.wangcong@...il.com>
Cc:     Dinan Gunawardena <dinan.gunawardena@...ronome.com>,
        netdev@...r.kernel.org, oss-drivers@...ronome.com,
        Benjamin LaHaise <benjamin.lahaise@...ronome.com>,
        Simon Horman <simon.horman@...ronome.com>
Subject: [PATCH/RFC net-next v2 0/4] net/sched: cls_flower: avoid false matching of truncated packets

Hi,

this series is intended to avoid false-positives which match
truncated packets against flower classifiers which match on:
* zero L4 ports or;
* zero ICMP code or type

This requires updating the flow dissector to return an error in such cases
and updating flower to not match on the result of a failed dissection.

In the case of UDP this results in a behavioural change to users of
flow_keys_dissector_keys[] and flow_keys_dissector_symmetric_keys[] -
dissection will fail on truncated packets where the IP protocol of the
packets indicates ports should be present (according to skb_flow_get_ports()).

The last patch of the series builds on the above to allow users to specify
a policy for how to handle packets whose dissection fails.

I will separately provide RFC patches to iproute2 to allow exercising the
last patch.

Changes between RFCv1 and RFCv2
* Rename new attribute in last path TCA_FLOWER_META_TRUNCATED
  after discussion with Jamal.
* Update changelog for "flow dissector" patches to make it clearer what
  the before and after behaviours are.

Simon Horman (4):
  flow dissector: return error on port dissection under-run
  flow dissector: return error on icmp dissection under-run
  net/sched: cls_flower: do not match if dissection fails
  net/sched: cls_flower: allow control of tree traversal on packet parse
    errors

 include/linux/skbuff.h       |  11 +++--
 include/uapi/linux/pkt_cls.h |   2 +
 net/core/flow_dissector.c    | 105 ++++++++++++++++++++++++-------------------
 net/sched/cls_flower.c       |  46 ++++++++++++++-----
 4 files changed, 106 insertions(+), 58 deletions(-)

-- 
2.1.4