[PATCH v6 net 0/4] net/sched: Fixes for sch_ingress and sch_clsact

[Peilin Ye <yepeilin.cs@gmail.com>]

Link to v5: https://lore.kernel.org/r/cover.1684887977.git.peilin.ye@bytedance.com/
Link to v4: https://lore.kernel.org/r/cover.1684825171.git.peilin.ye@bytedance.com/
Link to v3 (incomplete): https://lore.kernel.org/r/cover.1684821877.git.peilin.ye@bytedance.com/
Link to v2: https://lore.kernel.org/r/cover.1684796705.git.peilin.ye@bytedance.com/
Link to v1: https://lore.kernel.org/r/cover.1683326865.git.peilin.ye@bytedance.com/

Hi all,

These are v6 fixes for ingress and clsact Qdiscs, including only first 4
patches (already tested and reviewed) from v5.  Patch 5 and 6 from
previous versions are still under discussion and will be sent separately.
Per-patch changelog omitted.

Change in v6:
  - only include first 4 patches from previous versions

Changes in v5:
  - for [6/6], reinitialize @q, @p (suggested by Vlad) and @tcm after the
    "replay:" tag
  - for [1,2/6], do nothing in ->destroy() if ->parent isn't ffff:fff1, as
    reported by Pedro

Change in v3, v4:
  - add in-body From: tags

Changes in v2:
  - for [1-5/6], include tags from Jamal and Pedro
  - for [6/6], as suggested by Vlad, replay the request if the current
    Qdisc has any ongoing (RTNL-unlocked) filter requests, instead of
    returning -EBUSY to the user
  - use Closes: tag as warned by checkpatch

[1,2/6]: ingress and clsact Qdiscs should only be created under ffff:fff1
  [3/6]: Under ffff:fff1, only create ingress and clsact Qdiscs (for now,
         at least)
  [4/6]: After creating ingress and clsact Qdiscs under ffff:fff1, do not
         graft them again to anywhere else (e.g. as the inner Qdisc of a
         TBF Qdisc)
  [5/6]: Prepare for [6/6], do not reuse that for-loop in qdisc_graft()
         for ingress and clsact Qdiscs
  [6/6]: Fix use-after-free [a] in mini_qdisc_pair_swap()

[a] https://syzkaller.appspot.com/bug?extid=b53a9c0d1ea4ad62da8b

Thanks,
Peilin Ye (4):
  net/sched: sch_ingress: Only create under TC_H_INGRESS
  net/sched: sch_clsact: Only create under TC_H_CLSACT
  net/sched: Reserve TC_H_INGRESS (TC_H_CLSACT) for ingress (clsact)
    Qdiscs
  net/sched: Prohibit regrafting ingress or clsact Qdiscs

 net/sched/sch_api.c     | 12 +++++++++++-
 net/sched/sch_ingress.c | 16 ++++++++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

-- 
2.20.1