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Date: Thu, 21 May 2026 08:56:02 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Davide Caratti <dcaratti@redhat.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>, Rajat Gupta
 <rajat.gupta@oss.qualcomm.com>, netdev@vger.kernel.org,
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 horms@kernel.org, jiri@resnulli.us, yimingqian591@gmail.com,
 keenanat2000@gmail.com, 2045gemini@gmail.com, rollkingzzc@gmail.com
Subject: Re: [PATCH net] net/sched: fix pedit partial COW leading to page
 cache corruption
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On Thu, 21 May 2026 17:51:25 +0200 Davide Caratti wrote:
> >  Do you know of anyone modifying payloads with pedit?  
> 
> yes: MPTCP kselftest does that on purpose, to mimic a middlebox and trigger
> DSS checksum failures [1]

As I said in another reply (looks like the ML is having a significant
lag this morning :() - we would still support it, the shared frag
tracking is just an optimization to avoid a copy. And maintaining that
optimization for an occasional CI test is not the right eng tradeoff.