From: Jakub Kicinski <kuba@kernel.org>
To: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
horms@kernel.org, andrew+netdev@lunn.ch, netdev@vger.kernel.org,
xiyou.wangcong@gmail.com, jiri@resnulli.us, victor@mojatatu.com,
dcaratti@redhat.com, lariel@nvidia.com, daniel@iogearbox.net,
pablo@netfilter.org, kadlec@netfilter.org, fw@strlen.de,
phil@nwl.cc, netfilter-devel@vger.kernel.org,
coreteam@netfilter.org
Subject: Re: [PATCH net 0/6] net/sched: Fix packet loops in mirred and netem
Date: Wed, 14 Jan 2026 19:28:07 -0800 [thread overview]
Message-ID: <20260114192807.2f83a4bb@kernel.org> (raw)
In-Reply-To: <CAM0EoMmZA_1R8fJ=60z_dvABpW3-f0-5WhYzpn1B1uY9BA4x4A@mail.gmail.com>
On Wed, 14 Jan 2026 11:40:18 -0500 Jamal Hadi Salim wrote:
> On Tue, Jan 13, 2026 at 9:07 PM Jakub Kicinski <kuba@kernel.org> wrote:
> > On Sun, 11 Jan 2026 11:39:41 -0500 Jamal Hadi Salim wrote:
> > > We introduce a 2-bit global skb->ttl counter.Patch #1 describes how we puti
> > > together those bits. Patches #2 and patch #5 use these bits.
> > > I added Fixes tags to patch #1 in case it is useful for backporting.
> > > Patch #3 and #4 revert William's earlier netem commits. Patch #6 introduces
> > > tdc test cases.
> >
> > TC is not the only way one can loop packets in the kernel forever.
> > Are we now supposed to find and prevent them all?
>
> These two are trivial to reproduce with simple configs. They consume
> both CPU and memory resources.
> I am not aware of other forever packet loops - but if you are we can
> look into them.
Is there loop prevention in BPF redirect? Plugging two ends of veth
into a bridge? Routing loops with an action to bump TTL back up?
next prev parent reply other threads:[~2026-01-15 3:28 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-11 16:39 [PATCH net 0/6] net/sched: Fix packet loops in mirred and netem Jamal Hadi Salim
2026-01-11 16:39 ` [PATCH net 1/6] net: Introduce skb ttl field to track packet loops Jamal Hadi Salim
2026-01-13 19:44 ` Cong Wang
2026-01-11 16:39 ` [PATCH net 2/6] net/sched: Fix ethx:ingress -> ethy:egress -> ethx:ingress mirred loop Jamal Hadi Salim
2026-01-11 16:39 ` [PATCH net 3/6] Revert "net/sched: Restrict conditions for adding duplicating netems to qdisc tree" Jamal Hadi Salim
2026-01-11 16:39 ` [PATCH net 4/6] Revert "selftests/tc-testing: Add tests for restrictions on netem duplication" Jamal Hadi Salim
2026-01-11 16:39 ` [PATCH net 5/6] net/sched: fix packet loop on netem when duplicate is on Jamal Hadi Salim
2026-01-11 20:22 ` William Liu
2026-01-11 20:39 ` Cong Wang
2026-01-11 21:56 ` Jamal Hadi Salim
2026-01-13 19:32 ` Cong Wang
2026-01-11 16:39 ` [PATCH net 6/6] selftests/tc-testing: Add netem/mirred test cases exercising loops Jamal Hadi Salim
2026-01-13 6:20 ` [PATCH net 0/6] net/sched: Fix packet loops in mirred and netem Stephen Hemminger
2026-01-13 19:35 ` Cong Wang
2026-01-13 20:10 ` Cong Wang
2026-01-14 16:33 ` Jamal Hadi Salim
2026-01-15 20:16 ` Cong Wang
2026-01-16 15:04 ` Jamal Hadi Salim
2026-01-14 2:07 ` Jakub Kicinski
2026-01-14 16:40 ` Jamal Hadi Salim
2026-01-15 3:28 ` Jakub Kicinski [this message]
2026-01-15 10:22 ` Paolo Abeni
2026-01-15 14:32 ` Jamal Hadi Salim
2026-01-29 5:06 ` Willem de Bruijn
2026-01-29 21:22 ` Jamal Hadi Salim
2026-02-28 13:05 ` Jamal Hadi Salim
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