From: Jakub Kicinski <kuba@kernel•org>
To: Victor Nogueira <victor@mojatatu•com>
Cc: netdev@vger•kernel.org, jhs@mojatatu•com,
xiyou.wangcong@gmail•com, jiri@resnulli•us, davem@davemloft•net,
edumazet@google•com, pabeni@redhat•com, toke@redhat•com,
gerrard.tai@starlabs•sg, pctammela@mojatatu•com
Subject: Re: [PATCH net v2 0/5] net_sched: Adapt qdiscs for reentrant enqueue cases
Date: Thu, 17 Apr 2025 09:07:28 -0700 [thread overview]
Message-ID: <20250417090728.5325e724@kernel.org> (raw)
In-Reply-To: <20250416102427.3219655-1-victor@mojatatu.com>
On Wed, 16 Apr 2025 07:24:22 -0300 Victor Nogueira wrote:
> As described in Gerrard's report [1], there are cases where netem can
> make the qdisc enqueue callback reentrant. Some qdiscs (drr, hfsc, ets,
> qfq) break whenever the enqueue callback has reentrant behaviour.
> This series addresses these issues by adding extra checks that cater for
> these reentrant corner cases. This series has passed all relevant test
> cases in the TDC suite.
Sorry for asking this question a bit late, but reentrant enqueue seems
error prone. Is there a clear use case for netem as a child?
If so should we also add some sort of "capability" to avoid new qdiscs
falling into the same trap, without giving the problem any thought?
next prev parent reply other threads:[~2025-04-17 16:07 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-16 10:24 [PATCH net v2 0/5] net_sched: Adapt qdiscs for reentrant enqueue cases Victor Nogueira
2025-04-16 10:24 ` [PATCH net v2 1/5] net_sched: drr: Fix double list add in class with netem as child qdisc Victor Nogueira
2025-04-23 0:44 ` Jakub Kicinski
2025-04-23 14:41 ` Victor Nogueira
2025-04-16 10:24 ` [PATCH net v2 2/5] net_sched: hfsc: Fix a UAF vulnerability " Victor Nogueira
2025-04-16 10:24 ` [PATCH net v2 3/5] net_sched: ets: Fix double list add " Victor Nogueira
2025-04-16 10:24 ` [PATCH net v2 4/5] net_sched: qfq: " Victor Nogueira
2025-04-16 10:24 ` [PATCH net v2 5/5] selftests: tc-testing: Add TDC tests that exercise reentrant enqueue behaviour Victor Nogueira
2025-04-17 16:07 ` Jakub Kicinski [this message]
2025-04-17 21:49 ` [PATCH net v2 0/5] net_sched: Adapt qdiscs for reentrant enqueue cases Victor Nogueira
2025-04-22 11:34 ` Paolo Abeni
2025-04-17 19:23 ` Cong Wang
2025-04-17 22:13 ` Victor Nogueira
2025-04-22 11:21 ` Paolo Abeni
2025-04-23 20:50 ` Cong Wang
2025-04-23 23:29 ` Cong Wang
2025-04-24 0:24 ` Jakub Kicinski
2025-04-24 15:22 ` Jamal Hadi Salim
2025-04-24 15:40 ` Jamal Hadi Salim
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